THE NEW ZEALAND OFFICIAL YEAR-BOOK 1931

The total area of the Dominion of New Zealand, which does not include the territories administered under mandate, the Ross Dependency, and the Tokelau Islands, is 104,015 square miles. The areas of the principal islands are as follows:—

Elsewhere in this volume the aggregate area of the land districts of New Zealand is shown as 66,390,262 acres, i.e., 103,735 square miles. This area covers net only the Dominion proper but also the outlying islands and the Kermadecs.

The mountainous character of New Zealand is one of its most striking physical characteristics. In the North Island mountains occupy approximately one-tenth of the surface; but, with the exception of the four volcanic peaks of Egmont (8,260 ft.), Ruapehu (9,175 ft.), Ngauruhoe (7,515 ft.), and Tongariro (6,458 ft.), they do not exceed an altitude of 6,000 ft. Of these four volcanoes only the first-named can be classed as extinct. Other dormant volcanoes include Mount Tarawera and White Island, both of which have, in recent years, erupted with disastrous consequences. Closely connected with the volcanic system are the multitudinous hot springs and geysers.

The South Island contains much more mountainous country than is to he found in the North. Along almost its entire length runs the mighty chain known as the Southern Alps, rising to its culmination in Mount Cook (12,349 ft.). No fewer than seventeen peaks of the Southern Alps attain a height of over 10,000 ft. Owing to the snow-line being low in New Zealand, many large and beautiful glaciers exist. The Tasman Glacier (Southern Alps), which has a total length of over eighteen miles and an average width of one mile and a quarter, is the largest. On the west coast the terminal faces of the Franz Josef and Fox Glaciers are hut a few hundred feet above sea-level.

The following list of named peaks over 7,500 ft. in height has been compiled from various sources. It does not purport to cover all such peaks, nor is exactitude claimed in respect of the elevations shown, many of which are known to be only approximate.

The hot springs of the North Island form one of the most remarkable features of New Zealand. They are found over a large area, extending from Tongariro, south of Lake Taupo, to Ohaeawai, in the extreme north—a distance of some three hundred miles; but the principal seat of hydrothermal action appears to be in the neighbourhood of Lake Rotorua, about forty miles north-north-east from Lake Taupo. By the destruction of the famed Pink and White Terraces at Lake Rotomahana during the eruption of Mount Tarawera on the 10th June, 1886, the neighbourhood was deprived of attractions unique in character and of unrivalled beauty; but the natural features of the country—the numerous lakes, geysers, and hot springs, some of which possess remarkable curative properties in certain complaints—are still very attractive to tourists and invalids. The importance of conserving this region as a sanatorium for all time has been recognized by the Government, and it is dedicated by Act of Parliament to that purpose.

There are also several small hot springs in the South Island, the best known being these at Hanmer.

The following article on the mineral waters and spas of New Zealand is by the Government Balneologist, Dr. J. D. C. Duncan, M.B., Ch.B. (Edin.), Member of the International Society of Medical Hydrology, Fellow of the Royal Society of Medicine, and Fellow of the Royal Geographical Society:—

It has been acknowledged by the leading hydrologists in Europe that New Zealand possesses the most valuable mineral waters in existence. Not only are these mineral waters interesting from a tourist's point of view, but they are, because of their medicinal value, of great therapeutic importance, and, as a Dominion asset, worthy of the deepest scientific consideration.

From the spectacular aspect only a brief mention need be made in this article, as a full description of springs, geysers, and mud-pools has been given in Dr. Herbert's book, “The Hot Springs of New Zealand”—a book that presents a comprehensive and vivid picture of the main manifestations of thermal activity in New Zealand.

Dealing with the medical-scientific aspect of the mineral waters, the space of this article will permit only the shortest account of the treatments; and, as the Rotorua Spa is of premier importance, the article will be confined almost entirely to its operations.

Since and as the result of experience gained during the war, the subject of hydrotherapy has been recreated on modern scientific lines, and the actions of thermal mineral waters have been investigated, both chemically and physiologically, in determining their therapeutic value in the treatment of disease.

The mineral waters which have been harnessed for therapeutic use at the Rotorua Spa are of two main varieties—viz., the “Rachel,” which is an alkaline, sulphuretted water, emollient to the skin, and sedative in reaction; and the “Priest,” or free-acid water, which, due to the presence of free sulphuric acid, is mainly stimulating and tonic in reaction. There is, in addition to the foregoing, a valuable silicious mud similar to that found in Pistany, in Czecho-Slovakia, which, in its own sphere, in hydrotherapy, exerts its influence as a curative agent.

However, it is in the “Priest” waters that one finds one's most valuable ally in the treatment of arthritis, fibrositis (the so-called rheumatic affections), and cases of nervous debility. The “Rachel” and mud baths are used mostly in these cases of fibrositis where the condition requires a softening effect; and in the types where pain is a manifest symptom these baths are invaluable as soothing and sedative agents.

In these natural acid baths the reactions are mainly stimulating, with increased hyperæmia in the parts submerged, and marked lessening of pain and swelling in the affected joints and tissues. These waters containing free carbonic-acid gas are used for the cases of fibrositis in which the circulation requires the stimulating action of gaseous baths.

The “New Priest” waters, containing approximately 16.80 grains per gallon of free sulphuric acid, are utilized in the form of open pools, deep step-down baths, and slipper baths. They are prescribed at a suitable temperature for the individual case.

The “Old Priest” waters, containing a much lower degree of free acid (3.77 grains to the gallon), and of varying temperatures (from 84° F. to 102° F.), are used for treatment at their source. The waters, percolating through their pumice-bed, are confined in pools, and contain free carbonic-acid gas bubbling through the water.

The very strong “Postmaster” waters are also confined within pools on the natural pumice-bed, and, by a primitive arrangement of wooden sluice-valves, are maintained at three ranges of temperature—viz., 104°, 106°, and 108° F. They contain 22.29 grains of free sulphuric acid to the gallon, and are strongly counter-irritant in their reactions.

In such a brief account as this one can only deal in generalizations, and the forms of treatment mentioned must necessarily be subject to wide variations. In any form of hydro-therapeutic treatment the regime must be adapted to the individual manifestations of the disease, and no routine rules or regulations can be laid down in spa operations.

The “New Priest” waters are, for the most part, prescribed for patients suffering from subacute or chronic fibrositis, subacute or chronic gout, and the various forms of arthritis. Except in cases of marked debility, these patients are given graduated baths, at temperatures ranging from 102° to 104° F., from ten to fifteen minutes daily. Most of the baths are fitted with a subaqueous douche having a pressure of 25 lb. to the square inch, which is directed under water on the affected tissues. The bath is usually followed by a light or hot pack, according to the needs of the case.

The subthermal “Old Priest” waters (temperature 84° F.), containing a high degree of free carbonic - acid gas, are particularly valuable in the treatment of functional nervous disease, and the methods of administration are similar to these obtaining at Nauheim. The reactions are markedly stimulating through the sympathetic nervous system, and bring about, by reflex action, a tonic effect on the heart.

The “Postmaster” baths are used in the treatment of the more chronic forms of fibrositis, arthritis deformans, and gout, requiring a more or less heroic type of procedure. They are usually prescribed in combination—i.e., a certain time in each pool, commencing with the lowest temperature. The hyperæmic reaction is most marked, and in many of the cases where pain is a predominant symptom there is a temporary paralysis of the surface nerves, as well as a strong reflex excitation of the heart. For this reason these baths are not given to patients suffering from cardiac weakness.

The mud baths being highly impregnated with silica, which has a bland sedative effect on the tissues, are particularly indicated in cases of acute or subacute neuritis, gout, and certain skin conditions. The action of these baths is to induce an active hyperæmia in the patient with an actual absorption of free sulphur, which is present in considerable quantity. Also the radio-activity of this medium (0.185 per c.c.) is possibly an active factor in the therapeutic action of these baths. In some of the cases undergoing mud-bath treatment the effect has been almost miraculous—instant relief from pain; reduction of swelling caused by inflammatory exudates—and such patients have been able to discard crutches or other adventitious aids and to walk with more or less normal comfort.

Perhaps, of more recent date, the most efficacious effects of mud treatments have been manifested in cases of skin conditions—notably psoriasis: cases which have resisted all forms of drug treatment have cleared up in an almost magical manner; and so frequently have such cures been effected that one believes that the silicious mud of Rotorua has some markedly specific action as a therapeutic agent.

The treatment of gout depends entirely on the individual manifestations. In certain subacute and chronic types fairly high temperatures (104° to 106° F., with hot packs) of “Priest” water are employed, in order to hasten the absorption of exudates and the elimination of uric acid. In cases of acute gout more sedative measures are pursued, such as “Rachel” baths at neutral temperatures, local mud packs, and rest. As soon as the conditions permit, these patients are changed over to acid water baths. Cases of chronic gout exhibiting metabolic stagnation sometimes receive considerable benefit from the counter-irritant effects of the strongly acid “Postmaster” waters.

Separate establishments, containing the most modern apparatus of sprays, douches, hot steam,. are available for wet massage and treatments of the Aix-Vichy type.

The massage-rooms are fitted with the latest installations of electrical equipment—Bristowe tables, diathermy, high frequency, Bergonie chair, X-ray, Schnée baths, Greville hot air, and other apparatus for carrying out the most up-to-date methods of electrical-therapeutic treatments.

The baths are administered by a trained staff of attendants, and the massage, electrical-therapy, and douches carried out by a qualified staff of operators.

In every respect the hydrotherapy treatments aim at a restoration of function, and the measures employed are, for the most part, re-educative.

In connection with the Rotorua Spa is a sanatorium of seventy beds, where patients whose finances are restricted can receive treatment at an exceedingly moderate cost. The institution consists of cubicles and open wards. Thermal baths and massage-rooms in the building provide for the more helpless type of invalid.

From sixty thousand to eighty thousand baths are given annually, and about thirty thousand special treatments—massage, electrical therapy,.—are administered each year at the Rotorua Spa.

The usual course of treatment lasts from four to six weeks, and the high percentage of cures and improvements testifies to the value of the thermal mineral waters and the hydro-therapeutic treatments obtaining in this Dominion.

The following account of the rivers of New Zealand is by Professor R. Speight, M.Sc., F.G.S., Curator of the Canterbury Museum:—

In a country like New Zealand, with marked variations in topographic relief and with a plentiful and well-distributed rainfall, the rivers must necessarily form characteristic features of the landscape. Mountains, however, exert an important influence on their adaptability to the necessities of commerce, reducing their value on the one hand while increasing it on the other. Owing to the steep grades of their channels few of the rivers are fitted for navigation except near their mouths, but to compensate for this disability they furnish in many places ideal sites for power plants. No country south of the Equator, except Chile and Patagonia, possesses such stores of energy conveniently placed, which cannot become exhausted until the sun fails to raise vapour from the neighbouring seas—a contingency to he realized only when life on the earth is becoming extinct.

The only part of the country which possesses rivers capable of being used for navigation is the North Island. The relief is not so marked as in the South, and many streams flow in deep beds, with somewhat sluggish current. There are flowing into the Tasman Sea rivers like the Waikato, Wairoa, Mokau, and Wanganui, which served the Maoris as important means of communication, and which are decidedly useful for the purposes of modern transport. The first-mentioned of these is by far the most important. Rising in the snows of Ruapehu, and receiving numerous affluents from the western slopes of the Kaimanawa Range, it pursues a northerly course for twenty miles with all the features of a mountain torrent till it enters Lake Taupo. Almost immediately on leaving this it plunges over the Huka falls, formed by a hard ledge of volcanic rock, and then runs first north-east and then north-west till it reaches the sea, the amount of water discharged exceeding 800,000 cubic feet per minute. In certain parts of its course the valley is gorgelike in character and picturesque rapids obstruct its navigation, but in its lower reaches it widens out and flows for long distances through marshes and shallow lakes, and empties into the sea by a wide estuary, which is unfortunately blocked by a bad bar. It receives on the west a large tributary, the Waipa—itself also navigable for small steamers, and a river which may ultimately play no small part in the development of the south-western portion of the Auckland Province.

The Northern Wairoa shows features which resemble these of the Waikato. It rises in the hilly land of the North Auckland Peninsula, and flows south as a noble stream till it enters Kaipara Harbour, a magnificent sheet of water with many winding and far-reaching arms, but with its utility greatly discounted by the presence of a bar which, though with sufficient depth of water for vessels of moderate size, is frequently impracticable. The total estimated discharge from the streams running into the Kaipara Harbour is about 500,000 cubic feet per minute, of which the Wairoa certainly contributes one-half.

The Mokau River, which enters the sea about sixty miles north-east of New Plymouth, is navigable for a considerable distance in its lower reaches. Here it is flanked by limestone bluffs, clad with a wealth of ferns and other native vegetation, forming one of the most picturesque rivers of the country. Higher up, as in the Waikato, there are fine falls, which may ultimately be used for power purposes owing to their proximity to one of the important agricultural districts of the North Island.

The last of the four principal navigable rivers on the west coast is the Wanganui. This river gathers its initial supplies from the western flanks of the volcanic ridge of the centre of the Island, from which numerous streams run west over the Waimarino Plain in somewhat open channels till they coalesce and form the main river. Other tributaries, such as the Tangarakau and the Maunganui-te-ao, subsequently add their quota, and the river then flows in a southerly direction in loops and windings depressed far below the level of the coastal plain, between high papa bluffs clad with rich vegetation, till it reaches the sea as a deep tidal stream, the amount of its discharge being estimated at over 500,000 cubic feet per minute. Through the greater part of its course it has a characteristic trench-like channel, with a fairly even gradient, and with only slight interruptions from rapids. At low water these are most troublesome, but at times of high river-level they are passed without serious difficulty. This fine stream affords communication into a country difficult of access by road or railway, and it may be taken as typical of other smaller streams to the west, such as the Waitotara, the Patea, and the Waitara, which are navigable to a less extent, principally owing to the obstructions of timber in their channels; while the rivers lying more to the east and with courses parallel to the Wanganui—e.g., the Rangitikei and the Wangaehu—are more rapid and Lave little adaptability to the needs of transport. Further cast still, in the neighbourhood of the Ruahine Mountains, the rivers become true mountain torrents, with steep grades and rapid currents.

On the other coast of the North Island the only streams capable of being used for navigation except just at their mouths are these running into the Firth of Thames—the Piako and the Waihou. But no account of our navigable rivers would be complete without a reference to the “drowned rivers” winch characterize the northern parts of the Island. The Kaipara may be taken as a typical case of such, for the harbour merely represents the depressed and sunken lower reaches of the Wairoa and other streams. A further notable case is the Hokianga River, which runs for twenty miles between wooded hills and receives numerous tributaries from them, tidal for a considerable part of their courses, and allowing water communication to be used for at least fifteen miles from the point where actual discharge into the open sea takes place.

The remaining rivers of the North Island of any importance rise in the mountain axis that stretches from near Wellington towards the eastern margin of the Bay of Plenty. Towards the southern end, where it lies close to the shore of Cook Strait, the rivers from it are short and swift, the only exception being the Manawatu, which has cut a deep gorge in the mountain barrier and drains an extensive basin lying on the eastern flanks of the Ruahine Range to the north, and of the Tararua Range to the south, as well as a considerable area of country on the slopes of the Puketoi Range, its headwaters in this direction reaching nearly to the east coast of the Island. The Manawatu has an estimated discharge of over 600,000 cubic feet per minute, and judging by this it must be considered the second largest river in the North Island. Although the Manawatu is the only stream which has succeeded up to the present in cutting through the range at its head, several of the rivers flowing west have eaten their way far back, and in future ages will no doubt struggle with the Manawatu for the supremacy of that tract of land lying to the cast of the range. Remarkable changes are likely to occur in the direction of drainage, especially if the earth-movements now in progress in the neighbourhood of Cook Strait continue for any lengthy period.

The central and southern parts of the Tararua and Rimutaka Ranges are drained by the Ohau, Otaki, Waikanae, and other streams flowing into Cook Strait; by the Hutt River, which flows into Wellington Harbour; and by the Ruamahanga and its tributaries, flowing through the Wairarapa Plain. These last include within their basins some amount of papa-country as well as steep mountain-slopes. While in the former they run in deep narrow channels, but when free from it they spread at times over wide shingly beds in a manner more characteristic of the streams of the South Island.

Several large rivers rise in the Ruahine Mountains and their northerly extensions. The chief of these flowing into Hawke Bay are the Ngaururoro, Tukituki, Mohaka, and Wairoa, the first being noteworthy for the enormous amount of shingle it has brought down; while farther north the Waipaoa runs into Poverty Bay and the Waiapu into the open sea, both draining an extensive area of rich papa land. From the north-western side of the range the Whakatane and the Rangitaiki, two considerable streams, flow into the Bay of Plenty.

The chief factor which determines the characters of the rivers of the South Island is the great mountain mass of the Southern Alps, with its extensions and semi-detached fragments. Its general direction is parallel to the west coast of the Island, and nearer to this coast than to the eastern one; it also lies right athwart the path of the wet westerly winds which prevail in these latitudes. The moisture collected during their passage across the Tasman Sea is precipitated in the form of rain on the coastal plain and the hills behind it, while the mountain-tops intercept it chiefly in the form of snow, the amount of annual rainfall varying from about 100 in. at sea-level up to over 200 in. near the main divide. The eastern slopes of the range receive less rain, and are increasingly drier as the coast is approached, but there the amount is slightly augmented by moist winds coming from the open ocean to the east. In the higher mountain valleys on both sides of the range lie numerous glaciers, either of the small cliff type or large ones of the first order, the most notable being the Tasman, Hooker, Mueller, Godley, Rangitata, Lyell, and Ramsay on the east, and the Franz Josef and Fox on the west. The chief large rivers of the central district of the Island rise from the terminals of the glaciers and issue from the ice as streams of considerable volume. They reach their highest level in spring and summer, for not only does the heavier rainfall of that time of the year serve to swell them inordinately, but the snow and ice are melted under the combined influence of the rain itself and of the strong sun-heat. Although they are almost always more or less turbulent and dangerous to the traveller who attempts to ford them—in the warm months of the year they are liable to sudden and serious floods, and formerly they frequently blocked communication for weeks at a stretch—now, however, many of the worst streams have been bridged, and communication is thus easier and less precarious.

The general form of these valleys is of a fairly uniform type. Their heads are usually amphitheatre - like in shape, and for some distance they are occasionally covered by old moraines, and the course of the stream is impeded by huge angular blocks washed out of these or shed from the steep slopes; at times, too, the rivers flow through deep and somewhat narrow gorges. Lower down the valleys open out, with even steep sides, nearly perpendicular at times, and with flat floors covered by a waste of shingle, over which the rivers wander in braided streams. The sides are clad with dense bush for a height of approximately 2,500 ft., that merges into a tangle of subalpine scrub, to be succeeded after another 1,000 ft. by open alpine meadow, gradually passing upward into bare rock and perpetual snow.

After leaving the mountains the streams flowing to the West Coast cross the narrow fringe of aggraded coastal plain, and cut down their channels through old glacial drifts which furnished in former times rich leads of alluvial gold. The mouths of these rivers are usually blocked by shallow bars, but after heavy floods a channel may be scoured out, only to be closed, when the river falls, by the vast quantities of drift material moved along the beach by the heavy seas and the strong shore currents which sweep the open coast. It is only where it is possible to confine the river-mouths and direct their scour that open channels can be permanently maintained, and even these entrances are at times extremely dangerous to shipping.

The chief rivers which flow from the central portion of the Southern Alps to the Tasman Sea are the Taramakau, Hokitika, Wanganui, Wataroa, Waihao, Karangarua, Haast, and Arawata. All rise in glaciers, and their valleys are remarkable for their magnificently diversified bush and mountain scenery. Occasionally lakes, ponded back behind old moraines or lying in rock-bound basins and fringed with primeval forest, lend charm to the landscape, and make a journey along the West-land Plain one of the most delightful in New Zealand from the scenic point of view.

Farther north glaciers are absent, but the heavy rain feeds numerous large streams and rivers, the most notable being the Grey and the Buller, the latter being in all probability the largest on the west coast, the amount of its discharge being estimated at nearly 1,000,000 cubic feet per minute.

The general features of the rivers which flow into the West Coast Sounds are somewhat similar, except that few rise in glaciers, and there is no fringe of plain to the mountains. The valleys have steeper sides, waterfalls and lakes are more common, and are ideally situated for power installations. One of the large rivers of this area is the Hollyford, which flows into Martin's Bay; but the largest of all is the Waiau, which drains the eastern side of the Sounds region, receives the waters of Lakes Te Anau, Manapouri, and Monowai, and enters the sea on the south coast of the Island.

The rivers on the eastern slope of the Alps present features similar to these of the west coast in their upper courses, but the valleys are broader and flatter, floored from wall to wall with shingle and frequently containing large lakes of glacial origin. In these cases where lakes do not now exist there are undoubted signs that they occurred formerly, having been emptied by the erosion of the rock-bars across theirlower extremities and filled at the same time by detrital matter poured in at their heads.

The largest of all these rivers is the Clutha; in fact, it discharges the greatest volume of water of any river in New Zealand, the amount being estimated at over 2,000,000 cubic feet per minute. The main streams which give rise to this river flow into Lakes Wanaka and Hawea, and have their sources in the main divide to the north of the ice-clad peak of Mount Aspiring and in the neighbourhood of the Haast Pass. After flowing as a united stream for nearly thirty miles it receives from the west a tributary nearly as large as itself called the Kawarau, whose discharge has been accurately gauged by Professor Park at 800,000 cubic feet per minute. This great volume of water is due to the fact that the Kawarau drains Lake Wakatipu, which serves as a vast reservoir for the drainage of a considerable area of mountain country, including snow-clad peaks at the head of the lake. The united streams continue in a south-easterly direction, and their volume is substantially increased by the Manuherikia on the east bank as well as by the Pomahaka on the west. The course of the Clutha lies through the somewhat arid schist region of Central Otago, gorge alternating with open valley and river-flats; but some ten miles or so before it reaches the sea it divides, only to reunite lower down and thus include the island known as Inch-Clutha. It almost immediately afterwards enters the sea, but its outlet is of little use as a harbour owing to a shifting and dangerous bar. Portions of its course are navigable to a very limited extent, but it is more important commercially, since it has yielded by means of dredging operations great quantities of gold; in fact, it may be regarded as a huge natural sluice-box, in which the gold disseminated through the schists of Central Otago has been concentrated through geological ages into highly payable alluvial leads.

The following large rivers belong to the Southland and Otago District, but do not reach back to the main divide—the Jacobs, Oreti, Mataura, and Taieri; and forming the northern boundary of the Otago Provincial District is the Waitaki, which drains a great area of alpine country, and includes in its basin Lakes Tekapo, Pukaki, and Ohau. Its main affluents are the Tasman and the Godley, rising in glaciers of the same names near the axis of the range where it is at its highest. As the river approaches the sea it crosses shingle-plains, through which it has cut a deep channel flanked by terraces, which rise bench-like for some hundreds of feet above the present level of the river. Its general features are similar to these of the rivers of Canterbury farther north, except that a larger proportion of the course of the latter lies across the plains and uninterfered with in any way by the underlying harder and more consolidated rocks. The four principal rivers which rise in glaciers are the Rangitata, Ashburton, Rakaia, and Waimakariri; while farther north are the Hurunui and Waiau, snow- and rain-fed rivers rising in the main range beyond the northerly limit of glaciers; and there are other streams—such as the Waihao, Pareora, Opihi, Selwyn, Ashley, and Waipara—which do not reach beyond the outer flanking ranges, and are almost entirely rain-supplied.

According to recent investigations the low-water discharge of the Waimakariri is approximately 80,000 cubic feet per minute, but it frequently rises in normal flood to 500,000 cubic feet per minute.

The rivers flowing to the east all carry down enormous quantities of shingle, but in former times they carried down even more, and built up the wide expanse of the Canterbury Plains by the coalescing and overlapping of their fans of detritus, the depth of shingle certainly exceeding 1,000 ft. Subsequently, when conditions, climatic or otherwise, slightly altered, they cut down deep through this incoherent mass of material, forming high and continuous terraces. Nowhere is the terrace system more completely developed than at the point where the rivers enter on the plains, for there the solid rock that underlies the gravels is exposed, and by the protection that it affords to the bases of old river flood-plains or former terraces it contributes materially to their preservation in a comparatively uninjured condition. The valleys of all these rivers are now almost treeless except in their higher parts, but there the mixed bush of West-land is replaced by the sombre beech forest; it is only in exceptional cases that the totara, which forms an important element of the bush on the hills to the west, crosses the range and covers portions of the sides of the valleys on the east.

Both the Hurunui and the Waiau have cut down gorges through semi-detached mountain masses of older Mesozoic rock, a result probably accelerated by the movements of the earth's crust; and farther north, in Marlborough, the Clarence, Awatere, and Wairau have their directions almost entirely determined by a system of huge parallel earth-fractures, running north-east and south-west, and the rivers are walled in on either side by steep mountains for the greater part of their length. The Clarence Valley is the most gorge-like, since it lies between the great ridges known as the Seaward and Inland Kaikouras, which reach a height of about 9,000 ft. The last river of the three, the Wairau, flows for a considerable distance through a rich alluvial plain, and enters Cloudy Bay by an estuary which is practicable for small steamers as far as the Town of Blenheim. The most important of the streams on the southern shores of Cook Strait are the Pelorus, Motueka, Takaka, and Aorere, great structural faults being chiefly responsible for the position and characteristic features of the valleys of the last two.

An important commercial aspect of our rivers is their use not only as drainage channels, but as a source of water for pastoral purposes. Hardly any area is without water for stock or with a subsoil wanting in moisture necessary for successful cultivation. Only in Central Otago and on the Canterbury Plains were there formerly wide stretches of arid country, but the deficiency in the water-supply has been remedied by well-engineered systems of races, tapping unfailing streams at higher levels, and distributing a portion of their contents far and wide, so that the districts mentioned are rendered highly productive and absolutely protected from the serious effects of drought. It is, however, the rich alluvial fiats and well-drained terrace lands bordering on the rivers that contribute specially to the high average yield per acre year after year for which this country has such a world-wide reputation.

From the brief summary given above it will be evident also that in her rivers the country possesses enormous stores of energy awaiting exploitation. A beginning has been made in some places, such as at Waipori in Otago, at Lake Coleridge in Canterbury, at the Horahora Falls and at Arapuni on the Waikato River, at Mangahao in Wellington, at Lake Waikaremoana, and at a few other places where there are minor installations. These owe their development to their comparative nearness to centres of industry; but they represent an infinitesimal portion of the energy available, and the value of our vast store will be more truly appreciated when our somewhat limited reserves of coal show signs of failure or become difficult to work—unless, indeed, some new form of power is disclosed by the researches of science in the near future.

A list of the more important rivers of New Zealand is given, with their approximate lengths, the latter being supplied by the Department of Lands and Survey.

The following article on the lakes of New Zealand is also by Professor R. Speight:—

Lakes are features of the landscape which are usually attributable to the filling-up of hollows formed by faulting or warping, or by volcanic explosions, or by the irregular accumulation of material round volcanic vents, or to the interference with river-valleys by glaciers. Seeing that all these agencies have operated on an extensive scale in New Zealand in comparatively recent geological times, it is not surprising that its lake systems are well developed. The remarkable group of lakes lying in the middle of the North Island, as well as isolated enclosed sheets of water in other parts of the Auckland Provincial District, are due to volcanic action in its various forms, while these in the South Island are to be credited to the operations of glaciers. We have therefore two distinct types of lake scenery—one for each Island. The relief of the land near the volcanic lakes is not by any means marked, and they therefore rarely have bold and precipitous shores, and their scenic interest depends partly on the patches of subtropical bush which grows luxuriantly in places on the weathered igneous material, and partly on their desolate and forbidding surroundings, everywhere reminiscent of volcanic action, where the softening hand of time has not reduced the outpourings of the eruptive centres to a condition favourable for the establishment of vegetation. The thermal activity which is manifested in numerous places on their shores adds to their interest. In the South Island the lakes lie in the midst of splendid mountain scenery, with amphitheatres of noble peaks at their heads, crowned with perpetual snow, and clad at lower levels with dark primeval beech forest, which affords an appropriate setting for the waters at their base, rendered milky-white at times with the finest of sediment worn from solid rocks by powerful glaciers, and swept down to the quiet waters of the lake by turbulent glacial torrents.

The largest sheet of fresh water in New Zealand is Lake Taupo, which is situated in the very heart of the North Island, at an elevation of 1,211 ft. above the sea. Its greatest length in a S.W.-N.E. direction is twenty-five miles, and its greatest breadth is about seventeen miles, but its shape is somewhat irregular owing to a large indentation on its western side. Its area is 238 square miles, its greatest depth is 534 ft., and it has a catchment area of about 1,250 square miles. About 60 per cent. of its water-supply comes from the Upper Waikato River, which drains the northern and eastern flanks of the central volcanoes as well as the western slopes of the Kaimanawa Range and its northern extensions. The lake discharges at its north-eastern corner, and forms the main Waikato River, which falls within a short distance over the Huka Falls, where the volume of water which passes over is estimated to reach an average of 5,000 cubic feet per second. The surroundings of the lake are picturesque, on the western side especially. Here it is bounded by cliffs of volcanic rock, generally between 100 ft. and 800 ft. in height, but at the Karangahape Bluffs they rise to over 1,000 ft. sheer. The northern shore is bold, with promontories terminated with bluffs and intervening bays with gentler slope. The south side is generally fringed with alluvial flats, while the east is bordered in places with pumice cliffs, and is somewhat uninteresting, but relieved from absolute monotony by the graceful extinct cone of Tauhara. About twenty miles to the south rise the great volcanic peaks of Tongariro, Ngauruhoe, and Ruapehu, with their bush-clad foothills, forming a splendid panorama when seen from the northern shore of the lake.

To the south-east of the middle of the lake lies the Island of Motutaiko, in all probability the summit of a volcanic cone on the line of igneous activity which stretches north - east from the central volcanoes towards Tarawera, White Island, Tonga, and Samoa. The formation of the lake itself is attributable either to a great subsidence after volcanic activity waned, or to a great explosion which tore a vast cavity in the earth's crust and scattered the fragments far and wide over the middle of the island; and evidence of declining igneous action is furnished by hot springs in the lake itself and near its shore, especially at the north-east corner near Wairakei and on the southern shore near Tokaanu. Earth-movements have in all probability continued down to recent times, for an old shore platform or wave-cut terrace surrounds the lake, indicating that its waters were formerly at a higher level, and changes in level of the ground on the northern shore of the lake, attended by local earthquakes, occurred during the year 1922.

The lake forms an enormous reservoir of power conveniently placed for exploitation; it is estimated that the Huka Falls would develop up to 38,000 horse-power, and its central position renders it peculiarly suitable for supplying a wide district.

To the south of Taupo, nestling in the hills between the great lake and the northern slopes of Tongariro, lies Roto-Aira, a beautiful sheet of water, three miles in length and with an area of five square miles. It discharges by the Poutu River into the Upper Waikato. The other lakes of this region are small in size and usually occupy small explosion craters on the line of igneous activity mentioned above.

A most interesting group of lakes lies in the midst of the thermal region to the north-cast of Taupo. These comprise the following: Rotorua, Roto-iti, Roto-ehu, and Rotoma, which belong to a system lying to the north-west of the area, and Tarawera, Rotokakahi, Tikitapu, Okareka, Rotomahana, Okataina, Rotomakariri, and Herewhakaitu, which lie to the south-east. The former group is connected either directly or indirectly with the Kaituna River basin, and the latter with the Tarawera River basin, both of which discharge their waters into the Bay of Plenty. All these lakes occupy either explosion craters or depressions due to subsidences of the crust or hollows formed by irregular volcanic accumulations. They lie at an elevation of about 1,000 ft. above the sea. The largest is Rotorua, which is nearly circular in shape, except for a marked indentation on the southern shore. It is 32 square miles in area, and 84 ft. deep, with flat shores; but in the middle, rather towards the eastern side, the picturesque and historical Island of Mokoia rises to a height of 400 ft. The lake discharges at its north-eastern corner by the Ohau Creek, into Lake Roto-iti, a shallow and irregular depression, which runs in turn into the Okere River. To the north-east lies the small lake of Roto-ehu, separated from it by low ground, and farther on lies the picturesque Rotoma, of still smaller size.

The largest lake of the south-eastern group is Tarawera, lying to the north and west of the mountain of the same name; discharging directly into it are Rotokakahi, Okareka, and Okataina, the last two by subterranean channels, while Tikitapu and Rotomahana are separated from it by comparatively narrow ridges.

All these lakes owe their interest to the thermal manifestations which occur in their vicinity, and to the remnants of beautiful bush which have survived the eruption of Tarawera in 1886. They are also noted for their fishing, being well stocked with trout. Their water is available for power purposes to a limited extent, and a small installation is placed near the low fall where the Okere River discharges from Lake Roto-iti.

Two small lakes of volcanic origin are situated on the peninsula north of Auckland: these are Takapuna and Omapere. The former lies close to the City of Auckland, and occupies a small explosion crater near the sea; while Omapere is between the Bay of Islands and Hokianga, in a shallow depression, which owes its origin to the obstruction of the Waitangi River by a lava-flow. It is three miles long by two wide, and is placed at a height of 790 ft. above the sea.

About forty miles from the east coast, in the Hawke's Bay District, lies the most important lake of Waikaremoana, twelve miles in length by about six miles and a quarter in breadth at its widest part, but with an extremely irregular outline; it has an area of twenty-one square miles. Its surface is 2,015 ft. above the sea, and it has a maximum depth of 846 ft. It discharges by the Wairoa River to the northern shore of Hawke Bay. This lake is most favourably situated for the development of water-power, and it is estimated that it would generate, owing to its admirable position, as much as 136,000 horse-power. A few miles to the northeast lies the small lake called Waikare-iti, which discharges into the large lake.

The only other inland lakes of any importance in this Island are these situated in the lower course of the Waikato River, the most noteworthy being Waikare and Whangape. The former has an area of nearly eleven square miles and has a depth of 12 ft.; the latter is smaller, with an area of only four square miles and a depth of 9 ft. These owe their origin to flooding of low-lying land alongside the river—in all probability attributable to a slight lowering of the land in this part of the country, with the consequent inability of the river to discharge its surplus water without a proper channel being maintained.

Along the coast-line, especially behind the fringe of dunes, numerous small lakes are found, such as Rotokawa, near Kaipara, and Horowhenua, near Levin; and a large sheet of water occurs near the mouth of the Wairarapa Valley, called Lake Wairarapa. The lake is very shallow, and is liable to remarkable variations in size owing to heavy floods from the neighbouring ranges. Between it and the sea is a considerable area of swampy ground in which are several small lakes, the largest of which, Lake Onoke, is separated from Palliser Bay by a narrow shingle-spit.

By far the great majority of the lakes of the South Island are dependent for their formation either directly or indirectly on the action of glaciers. They may be small tarns high on the mountains, large lakes occupying considerable lengths of old stream-valleys which have been overdeepened by the excavating power of ice during the Pleistocene glaciation, or lakes formed by the filling of hollows in the irregular heaps of debris laid down on' a plain at the base of the mountains or in a wide open valley. Accumulations of debris may also assist the first two causes in the formation of lakes, and some may owe the initial formation of their basins to tectonic causes, but these have been modified profoundly by other influences.

Included in the first class are numerous sheets of water from the size of small ponds upwards, found in all parts of the mountain region, but especially in the high plateau regions of western Otago, and to a limited extent in north-west Nelson. To the second group belong the large lakes of the eastern watershed of the Alps and a small number which drain west, such as Rotoroa and Rotoiti in the Buller Basin, while to the last must be assigned the majority of the lakes of Westland; but Brunner and Kanieri should perhaps be assigned to the second class.

Seeing that glaciation was not so intense in the northern portion of the Island, it is not surprising that the lakes of that region are small and few in number. Attention has, however, been drawn to Boulder Lake, in the valley of the Aorere River, since it might be used for power purposes in connection with the great deposit of iron-ore at Parapara. It is only 151 acres in extent, but it lies at an elevation of 3,224 ft., and is conveniently placed for the establishment of an electric-power plant. Farther south, near the head of the Buller, are two larger lakes—Rotoroa and Rotoiti—occupying ice-eroded valleys dammed at their lower ends by moraine. The former has an area of eight square miles, and the latter two and three-quarter square miles; their heights above the sea being respectively 1,470 ft. and 1,997 ft,, and Rotoiti being 228 ft. deep.

In the valley of the Grey River are two lakes of considerable size—viz., Brunner and Poerua. These are shrunken and separated parts of a former extensive sheet of water which was ponded back behind a great glacier moraine. Lake Brunner is five miles long by four broad, has an area of 15.9 square miles, is 280 ft. above sea-level, and 357 ft, deep. It is surrounded on two sides by high wooded granite peaks, and on the other two by low ground. It discharges by the Arnold River to the Grey, but a very slight change of level would turn it into the Taramakau.

Lake Kanieri, which lies in the basin of the Hokitika River at the base of Mount Tuhua, is a beautiful sheet of water. It is five miles long by one and three-quarters wide, has an area of eight square miles, is 422 ft. above sea - level, and 646 ft. deep. It owes its origin partly to the hollow formed behind an immense morainic dam and partly to the erosive action of the valley glacier. Farther south on the coastal plain of Westland are numerous small and picturesque lakes, wooded to the water's edge, lying behind heaps of glacial debris or in ice-eroded basins. The most notable of these are Ianthe and Mapourika, both of small size, the former with an area of only two square miles, at a height of 80 ft. above sea-level, and with a depth of 105 ft., and the latter remarkable for the fine panorama of mountain scenery, with Mount Cook in the background, which can be obtained from the shore of the lake. Along this strip of coast-line there are numerous lagoon-like expanses of water, cut off from the sea by areas of dune or of moraine, the chief of these being Mahinapua, which lies close to the Town of Hokitika. This is but 6 ft. above tide water, and has an area of one and a half square miles. The creek discharging from it is noted for the perfect reflections to be seen in the dark, peat-stained water.

On the eastern side of the main divide lie the great valley lakes which belong to the following river-basins: Hurunui—Lake Sumner; Rakaia—Lakes Coleridge and Heron; Waitaki—Lakes Tekapo, Pukaki, and Ohau; Clutha—Lakes Wanaka, Hawea, and Wakatipu; Waiau—Lakes Te Anau, Manapouri, and Monowai; Wairaurahiri—Lake Hauroko; Waitutu—Lake Poteriteri. These are all formed on the same plan; great glaciers have excavated the floor of a river-valley and have piled the debris across its lower portion, leaving a great hollow which was filled with water when the ice retreated. Even in these river-basins where no lakes now exist the traces of their former presence are evident; especially is this the case with the Waimakariri, Rakaia, and Rangitata Valleys. Besides these large lakes each valley has its quota of small ones, usually hidden away among the piles of moraine or ponded back behind shingle-fans. Among these small lakes should be noted the following: Tennyson, in the valley of the Clarence; Taylor, Sheppard, Katrine, and Mason, in the Hurunui; Pearson. Grassmere, and Letitia, in the valley of the Waimakariri; Evelyn, Selfe, Catherine, Ida, and Lyndon, in that of the Rakaia; Clearwater (or Tripp), Howard, and Acland, in the Ashburton; Alexandrina, in the Waitaki; Lochnagar, Hayes, and Moke, in the Clutha. In the valley of the Waiau there are numerous lakes of small size hidden away in bush-clad valleys, the chief of which is Mavora, which discharges into the main Waiau by way of its large tributary, the Mararoa. On the west coast of this region are also many insignificant lakes as far as size is concerned, such as Lake Ada, a well known beauty spot on the Milford Sound track, while farther north McKerrow, a lake of larger size, discharges into Martin's Bay.

The only other lakes in this Island that are worthy of mention are Waihola, Forsyth, and Ellesmere. The first mentioned occupies the lower portion of the Taieri plain, and drains to the sea by a deep winding gorge cut through a ridge of rock-covered hills, the gorge being tidal for the greater part of its length. Lakes Forsyth and Ellesmere lie on the coast immediately south of Banks Peninsula, both ponded back behind a great shingle-spit formed by the drift of material brought down by the rivers and carried north under the influence of a strong shore current. Both are very shallow and liable at times to be invaded by the sea. Ellesmere is sixteen miles long by about ten broad, and Forsyth is about six miles long by one in breadth.

Among all these lakes three stand pre-eminent for their scenic interest—Wakatipu, Te Anau, and Manapouri. The first-named is walled in on both sides by steep mountains which rise at the head of the lake to over 8,000 ft. in the Humboldt Range, and to over 9,000 ft. in Mount Earnslaw. Te Anau has an uninteresting eastern shore, but its western shore is broken into three great arms, whose impressive scenery is strongly reminiscent of that of Milford Sound and George Sound; while Manapouri, with its many bush-clad islets and its indented shore-line with innumerable sheltered coves and pebbly beaches, belongs to the same type as Dusky Sound, the most beautiful of all in the fiord region.

The lakes of Canterbury lie in a treeless area and owe their scenic interest principally to the background of snowy peaks, while Wanaka and Hawea are intermediate in character between them and the more southern lakes of Otago.

The following is a summary of the statistics of the chief lakes of New Zealand:—

A reference to the section of this book dealing with water-power will give an idea of the enormous amount of energy awaiting development in the lakes of thSouth Island. The only one yet utilized to any great extent for hydro-electric purposes is Coleridge, in Canterbury. Some use is also being made of Monowai. In the North Island, Waikaremoana is one of three great schemes which have been developed for supplying the hydro-electric requirements of the whole of the Island.

The following article on the geology of New Zealand was prepared by Dr. J. Henderson, M.A., F.N.Z. Inst., Director of the Geological Survey:—

New Zealand is a small country, but its geological history is as complex and as ancient as that of a continent. Land, though from age to age it varied greatly in area, outline, and elevation, must have persisted in the New Zealand area from the oldest Palæozoic or earlier. Long periods during which gentle regional oscillations and warpings, aided by the slow-acting forces of denudation, brought about gradual changes were interrupted by great revolutions, when earth-stresses ridged the crust into mountains and quickly altered the whole configuration of the land and sea-floor. For New Zealand the important geological periods are these that followed the two latest mountain-building movements—the Kaikoura deformation of late Tertiary time, and the Hokonui deformation of the early Cretaceous. The deposits laid down in the intervening period of relative crustal stability cover a large proportion of the land, and contain all the coal and most of the limestone of the Dominion. The soils on which grow the forests, pastures, and crops are of post-Tertiary age, and the great bulk of the gold has been won from deposits formed during the same period.

The oldest known fossiliferous rocks in New Zealand are the Ordovician slates and greywackes of west Nelson and south-west Otago. Lower unfossiliferous beds of the same great system extend southward from the northern area and outcrop in the Westport, Reefton, Greymouth, Ross, and Okarito districts. Above the fossil-bearing beds, but probably still of Ordovician age, are the black phyllites, quartzites, and marbles which outcrop continuously from Takaka to Mount Owen, and are again exposed in the upper basins of the Matakitaki, Maruia, and Grey Rivers. The similar rocks of western Otago probably also belong to this group. The complex of gneisses and schists of the same region, intruded by acid and basic plutonics, and usually considered of Archæan age, resembles the part of the Ordovician strata of western Nelson that has been similarly invaded and metamorphosed and may well be of early Palæozoic age. Different authorities assign the mica, chlorite, and quartz schists of Central Otago to ages that range from the Archæan to the Triassic. They are certainly Palæozoic or older, since they grade upward into greywackes that, at Clinton, contain Permian fossils.

Silurian rocks are certainly known only in the Baton and Wangapeka districts, and Devonian rocks at Wangapeka and Reefton. These beds, fossils from which have lately been examined in England, cover only small areas. But the old Geological Survey mapped wide tracts of country in Nelson and Otago, covered with beds of the Te Anau Series, as Devonian, and the correlation may well be correct, though the rocks are entirely unfossiliferous.

The Maitai Series, that forms the ranges on the south-east side of the Nelson lowlands, are probably of Carboniferous or Permo-Carboniferous age. Their position in the time scale and their correlation with rocks in other parts of New Zealand have provoked much discussion. Permian strata, as already stated, occur in Otago, where the area they cover may be considerable.

Richly fossiliferous late Triassic rocks are known in the Kawhia-Mokau district, near the City of Nelson, and at several localities in Canterbury and Otago. Except in Nelson and Canterbury, strata that contain fossils referable to several stages of the Jurassic succeed without observed unconformity. The broad belt of greywacke and argillite that forms the mountains of Canterbury and Marlborough, and continues as a narrower belt through Wellington to northern Hawke's Bay, is usually referred to the Trias-Jura. Similar rocks outcrop in the centre of the North Island and at many points in North Auckland. There are Upper Triassic molluscs in these beds at several localities, and the vertebra of a saurian with Triassic rather than Permian affinities was found near Wellington. Lithelogically the greywackes and argillites of this vast series differ somewhat from the rocks of similar type belonging to the Jurassic and Maitai series; they are therefore thought to be of older Triassic age, but may well range into the Permian. The schists occurring with them in the Kaimanawa, Kaikoura, Moorhouse, and Kirkliston Ranges are probably older.

The thick conglomerates conformably overlying the younger Jurassic shales of the Port Waikato, Kawhia, and Coromandel regions belong to either the youngest Jurassic or the oldest Cretaceous. Strata of early and middle Cretaceous age occur east of the main axis of New Zealand at several points from Marlborough to East Cape. Late Cretaceous beds are much more widely distributed, being known in North Auckland and in many localities along the eastern side of both Islands. They contain thick layers of black shale that give many indications of oil, which, however, has not yet been found in commercial amount. The oldest known workable coal-seams in New Zealand, these at Broken River, Malvern Hills, Shag Point, and Kaitangata, and perhaps some near Greymouth, are in young Cretaceous beds.

Tertiary rocks form the greater part of the North Island and are widely distributed in the South. As a whole they are weaker and more readily weathered than the older strata, and hence have given rise to less rugged country, now mostly cleared and grassed and forming productive pastoral land.

Eocene rocks are present in North Auckland, and probably also in the Gisborne, Hawke's Bay, and east Wellington districts. In the South Island they occur on the West Coast and in Canterbury and Otago, in which regions they contain valuable coal-seams worked at Westport, Reefton, Greymouth, Mount Somers, and Milton. Of the same age are the auriferous “cements” of the Tuapeka district that greatly enriched the gravels of the neighbouring streams and are themselves worked for gold.

In Oligocene time the maximum subsidence during the Tertiary occurred, and but little of the New Zealand area remained above sea-level at its close. The thick limestones of the Oamaru district and the contemporaneous limestone prominent in many parts of New Zealand are the younger deposits of this age. The older beds contain the extensive coal-measures of the North Auckland, Waikato, Charleston, and other coalfields.

Miocene strata cover large areas in both islands, and also outcrop in the Wanganui, Gisborne, and Hawke's Bay regions, where Oligocene beds are altogether absent. In North Taranaki, the Murchison basin, and parts of the West Coast, thick coal-measures of this age contain workable seams of brown coal.

During the Pliocene the New Zealand area, which had been intermittently rising since the close of the Oligocene, was greatly elevated and deformed. The earth-blocks from which the present mountains have been carved were uplifted from, or from near, sea-level, and New Zealand as it now is was roughly shaped out. In the South Island the deposits of this period are chiefly gravels deposited in structural depressions; but in the North, and especially in its southern half, there are thick and extensive shoal-water marine sediments. These, and the underlying Miocene strata, are the source of the petroleum found at New Plymouth.

The Pleistocene was a period of regional oscillation. While the land was high the mountains of the South Island were intensely glaciated, and great ice-streams, carrying vast bodies of debris, descended into the low country; after the highlands had been reduced in height through both denudation and decided subsidence the glaciers rapidly retreated, and are to-day represented by comparatively small remnants far in the mountains. While the ice was melting,' the rivers of the South Island were unusually active in transporting waste to the lowlands and the sea. At this time, too, as well as somewhat earlier, the volcanoes of the North Island ejected an abundant supply of fragmentary material, much of which was borne away by the streams and used in building plains.

The deposits of Pleistocene and Recent age are in New Zealand of greater economic importance than these of all other ages. The plains, river-flats, and lowlands generally were formed or profoundly modified during this period, and the soils that cover them produced. During the same time practically all the gold won from the gravels of the South Island was liberated from a hard matrix and concentrated into workable deposits, and the rich bonanzas of the lodes of Hauraki were formed by secondary enrichment. The land-oscillations of the period are also of economic importance, for New Zealand's abundant water-power is derived from streams that have not yet, owing to the recency of land-uplift, cut their valleys to grade. On the other hand, land-depression has provided harbours and valuable artesian basins in many parts of the Dominion.

Plutonic rocks intrude many of the Palæozoic and Mesozoic strata, and some of the formations show evidence of contemporaneous volcanic action. Of the plutonic rocks granite is much the most prominent, and it outcrops at many points in West Nelson, Westland, Otago, and Stewart Island. In Nelson there were at least two periods of intrusion, no doubt corresponding with the great mountain-folding movements of the late Pakæzoic and early Cretaceous times. The auriferous lodes of Reefton and other localities on the West Coast probably originated from the cooling magmas that formed the younger granites. Basic and ultra-basic rocks, the latter now largely altered to serpentine, occur in Nelson, Westland, Otago, and to a less extent, in North Auckland.

Though volcanoes are known to have existed in Mesozoic and Palæozoic times, they seem to have been more active during the Tertiary than in any earlier age. The vast pile of flow and fragmental rocks that form the Hauraki Peninsula and the range that continues it southward to Tauranga belong to this period. The gold-silver veins extensively worked at Coromandel, Thames, and Waihi are in these rocks, which southward are smothered by the rhyolitic pumice that vents in the Taupo-Rotorua zone ejected during the late Pliocene and Pleistocene. Thick showers of pumice from this region cover a large part of the centre of the. North Island and streams have carried the finer material to practically all the low-lying parts of the island. The volcanoes are still alive, as is evidenced by the steam-vents, hot springs, and geysers found in the depressed zone extending from Ruapehu to White Island. The volcanic rocks of Taranaki probably range from the Miocene to the Pleistocene in age. The basalts and scoria cones that occur so abundantly between Kawhia and the Bay of Islands belong for the most part to the late Pliocene and Pleistocene, though cones at Auckland City are probably Recent.

In the South Island the volcanoes appear to be quite dead, for the hot springs at Hanmer and near the alpine chain are due to other causes. In the middle Tertiary, however, there were outbursts at many points, the chief eruptions being at Banks Peninsula and about Dunedin.

In a short article it is impossible to give an adequate idea of what geological workers have accomplished in New Zealand, or of what they have yet to do in order that the wisest use may be made of the country's mineral and agricultural resources. For good general accounts the treatises of Professors Park and Marshall should he consulted, and for more detailed information the bulletins of the Geological Survey and the many papers that have appeared in the “Transactions of the New Zealand Institute.”

The following article dealing with earthquakes in New Zealand has been prepared by Dr. C. E. Adams. F.R.A.S., Government Astronomer and Seismologist, with the assistance of Dr. J. Henderson, Director of the Geological Survey.

Earthquake and volcanic activity are manifestations of the adjustments constantly occuring in the earth's crust. In the not far distant past, geologically speaking, a more or less continuous belt of mountains was raised up round the border of the great sunken area of the Pacific, and this belt as a whole is characterized by “chronic and acute seismicity.” At times the earthquakes occur within the belt itself, though a large proportion have their epicentres on its submerged frontal slope.

The South island of New Zealand and the eastern part of the North are on the crest of the great mountain ridge or crustal fold which forms a portion of the real border of the Pacific. This ridge maintains a relatively straight course north-north-east for 1,600 miles, nearly to Samoa. The Auckland Peninsula, part of a decidedly weaker fold, meets the main fold nearly at right angles in the Rotorua-Taupo volcanic region. The earthquakes of this seismically sensitive district, though they may be locally severe, are not usually felt far from their points of origin. On the other hand, the tectonic earthquakes that occur along the main earth-fold shake large areas, some of them being recorded on instruments throughout the world. These are caused by the slipping of earth-blocks against their neighbours along fractures and, fortunately for New Zealand, the most severe earthquakes have their origin along the great shears that probably cut the submerged flank of the main fold about 200 miles cast of the North Island. The crest in New Zealand is not straight or simply curved and the elevation is not constant: elongated uplifted areas, most of them in linear series though some overlap, form a continuous ridge.

Many great faults and fault-zones have been traced for long distances, but a few only have been active since European occupation. Movement along a north-trending fault seven miles west of Murchison raised the ground east of the fault about 15 ft., and caused it to shift north-west about 9 ft. The uplift gradually decreases eastward, and dies out sixteen miles from the fault, facts indicating a slight tilt of the earth-block toward the east. Recent levellings show that the block is sinking somewhat irregularly, a movement, no doubt, causing some of the innumerable local after-shocks still being felt in the area. Other sensible earth-movements occurred in connection with the Taupo earthquake series of 1922.^* the Amuri earthquake of 1888.^† the Wellington earthquake of 1855,^‡ and probably the Awatere earthquake of 1848.^§ There is also definite evidence of geologically recent differential movement of earth-blocks at several widely separated points in both islands.

The origins of the New Zealand seismic region will be seen to arrange themselves in groups as follows:—

Group I.—Earthquakes felt most strongly on south-east coast of North Island; the origins form a strip 180 miles from the coast, parallel to the axis of New Zealand, and to axis of folding of older rocks in Hawke's Bay. Chief shocks: 17th August, 1868; 7th March, 1890; 23rd and 29th July, 1904; 9th August, 1904 (intensity IX on R.-F. scale); 8th September, 1904; prob. 23rd February, 1863 (IX. R.-F.); .

According to the late Captain F. W. Button, P.R.S., the geological evidence shows that. New Zealand rose considerably in the older Pliocene period, and was then probably joined to the Chatham Islands. At a later period subsidence occurred, followed again by elevation m the Pleistocene period, with oscillations of level since. The seismic origins of this group are at the foot of a sloping submarine plateau, about two hundred miles wide, which culminates to the east-south-east in the Chatham Islands. This elevation is separated from the New Zealand coast by a trough from 1,000 to 2,000 fathoms in depth, which is widest and deepest between these origins and the mainland.

* P. G. Morgan: N.Z. Geological Survey; Annual Report for the year 1923, p. 10.

^† Alexander McKay; Reports of Geological Explorations during 1888—89. Wellington, 1890.

^‡New Zealand Government Gazette, Wellington, vol. 2, No. 14, 17th October, 1855, p. 116. Sir Charles Lyell, “The Principles of Geology,” tenth edition, 1868, vol. 2, p. 82. London: Joint Murray.

^§New Zealand Government Gazette, Auckland, vol. 1, No, 27, 13th November, 1848 and vol. 1, No. 29, 20th November, 1848. H. S. Chapman in Westminster Review, vol. 51, 1849.

Group II.—(a) South-east of Otago Peninsula. Shocks: 20th November, 1872, .

(b) A strip south-east of Oamaru. Shocks: February, 1876; April, 1876; .

(c) Many short and jerky, but generally harmless, quakes felt in Christchurch) Banks Peninsula, and mid-Canterbury. Chief shocks: 31st August, 1870; 27th December, 1888 (VII, R.-F.); . Focus of 1888 shock, sixteen miles long, from west-south-west to east-north-east, twenty-four to twenty-five miles below surface, being the deepest ascertained origin in the New Zealand region.

These origins form a line parallel to the general axis of the land. It is possible that the loading of the sea-floor by the detritus brought down by the rivers of Canterbury and Otago is a contributing cause of the earthquakes of this group.

Group III.—Wellington earthquakes of January, 1855, and Cheviot earthquakes of 16th November, 1901, and of 25th December, 1922 (VIII, R.-F.).

The origin of the earthquake of 1855 was probably the fault that forms the eastern boundary of the Rimutaka Range and the western boundary of the Wairarapa Valley.

The origin of the Cheviot earthquake of 1901 was probably in or near the southern continuation of this fault.

The great earthquakes of October, 1848, probably came from the same region as these of January, 1855. The chief shocks of both series did extensive damage to property, and caused the formation of large rifts in the earth's surface.

Group IV.—(a) Region about twenty-five to thirty miles in length, and ten miles or less in width, running nearly north-north-east from middle of Lake Sumner, about twenty miles below the surface, whence proceed most of the severer shocks felt from Christchurch to the Amuri, and a large number of minor shocks. Chief earthquakes: 1st February, 1868; 27th August to 1st September, 1871; 14th September and 21st October, 1878; 11th April, 1884; 5th December, 1881 (VIII, R.-F.), when Christchurch Cathedral spire was slightly injured; 1st September, 1888 (IX, R.-F.), when upper part of same spire fell, and still more severe damage was done in the Amuri district; 9th March, 1929 (IX, R.-F.).

(b) A small shallow origin not more than five to ten miles below the surface, a few miles south of Nelson. Earthquake: 12th February, 1893 (VIII to IX, R.-F.); chimneys thrown down and buildings injured.

(c) Origin in Cook Strait, north-north-east of Stephen Island, about ten miles wide, and apparently traceable with few interruptions nearly to mouth of Wanganui River; depth, fifteen miles or more. More than half the earthquakes recorded in New Zealand belong to this region; earthquake of 8th December, 1897 (VIII to IX, R.-F.), and other severer ones came from south-south-west end. Probably the first recorded New Zealand earthquake, felt by Captain Furneaux on the 11th May, 1773, belonged to this region. Also 8th May, 1929 (VIII, R.-F.), and 29th May, 1929 (VII, R.-F.).

(d) Taupo Earthquakes.—During June and July, 1922, earthquakes were almost continuous in the Taupo district. The shocks reached intensity VIII on the Rossi-Forel scale, and then gradually subsided. Conditions were practically normal by the end of the year. The shocks were restricted to a small area of country, and were felt most strongly at Taupo, Wairakei, and Oruanui. The disturbances were accompanied by-loud rumblings. No effect appears to have been produced on the thermal activities of the region. Considerable subsidence was reported along the north side of Lake Taupo in a general north-easterly direction.

Former smart shocks in this region were reported in September-October, 1897.

(e) Morrinsville Earthquakes.—During November and December, 1926, earthquakes similar to the Taupo ones of 1922 were felt in and around Morrinsville. The earthquakes were apparently of shallow origin, and were probably caused by a movement along a fault trending west-north-west on the eastern side of the Pakaroa Range. The average intensity of the shocks was about IV, although one shock reached VIII on the Rossi-Forel scale. As in the case of the Taupo earthquakes, there was no evidence of any variation in the thermal activities of the district.

(f) An origin near Mount Tarawera, with a large number of moderate or slight shocks, most, but not all, volcanic and local in character—e.g., these of September, 1866, and these of June, 1886, which accompanied and followed the well-known eruption of Mount Tarawera.

These origins of Group IV are nearly in a straight line on the map; on or near the same line are the origins of earthquakes felt in the Southern Lakes District (15th December, 1883, &c.), the volcanoes Ruapehu, Ngauruhoe, Tongariro, Tarawera, and White Island. It is evident that this line, which, like the rest, is parallel or nearly so to the general axis, is a line of weakness or of unstable equilibrium. Hence the adjusting movements that have caused earthquakes may have from time to time relieved the pressure of the rocks that restrained overheated steam and other volcanic agents from bursting out, and so may have led to volcanic eruptions; just as the series of earthquakes in Guatemala and in the Caribbean Sea in April and May, 1902, were the signs of movements in the great folds of that part of the earth's crust, in the course of which, the pressure in the Antillean Ridge being relieved, the volcanic forces below Mount Pelée in Martinique, and Mount Souffrière in St. Vincent, caused the disastrous eruptions of that year.

Group V.—Off the west coast of the North Island near Raglan and Kawhia. Chief shock: 24th June, 1891 (VII to VIII, R.-F.). The line joining this origin to that of the earthquake of 1st February, 1882, is parallel to the other lines of origin (Groups I to IV); but we have no data to establish any connection between them.

The numbers of earthquakes experienced in New Zealand during each month of the years 1921 to 1929 inclusive are given in the table following. The total number of shocks during this period was 2,538, the greater number of which occurred in 1922 (near Taupo), and in 1929 (near Murchison).

The figures representing the monthly means are also now shown in graphical form. It will be seen that a fairly marked period exists, having a maximum in winter, and minima in summer and autumn.

The next table gives the numbers of strong or severe shocks which occurred at different times of the day. The table includes 107 shocks during the years 1921 to 1929 inclusive; and, in order to eliminate personal effects of observers, only these shocks which reached or exceeded intensity VI, R.-F., have been taken into account .

The total number of shocks occurring in each three-hour interval is next represented graphically. A well-marked diurnal period is shown, having a maximum between 3 a.m. and 6 a.m. and a minimum between 3 p.m. and 6 p.m.

The outstanding seismic phenomenon of the year 1929 was the disastrous earthquake which visited the north-western portion of the South Island on the 17th June. This shock, which was distinctly felt over the whole of New Zealand, resulted in the loss of seventeen lives, and serious damage to property in the Buller district, South Island. A list of stations at which the shock reached or exceeded intensity VIII on the Rossi-Forel scale is given:—

As in the case of other great earthquakes, hundreds of after-shocks occurred, some of them severe enough to cause further alarm in the damaged areas. From the 17th June to the 31st December, 1929, 632 after-shocks were recorded on the seismographs at the Dominion Observatory, Wellington.

Three other severe earthquakes occurred during 1929, viz.:—

The next table gives the distribution of earthquakes in each month of 1929, the number occurring in each Island, and the maximum intensities.

The total number of shocks felt during the year was 678, 93 of which were felt in the North Island, and 624 in the South Island, 39 being felt in both Islands. The maximum intensity was between IX and X on the Rossi-Forel scale. This occurred at Murchison and Lyell on the 17th June. The lowest maximum intensities occurred in January, during which month no shocks above intensity IV were experienced. The maximum intensity of shocks felt in 1921 and 1922 was VIII; in 1923, VI: in 1921, VII: in 1921, 1926, 1927, and 1928. VIII.

The number of earthquakes during 1929 whose maximum intensity fell in different numbers of the Rossi-Forel scale is now given. The table shows that earthquakes of all intensities were recorded, intensity III leading in point of numbers.

The following article on the climate of New Zealand has been prepared by Dr. E. Kidson, M.A., D.Sc., Director of Meteorological Services:—

The problem of the classification of the climate of a country may be regarded from various aspects. First of all, there is its solar climate, which depends on the amount of heat it receives from the sun and the variations of this amount with the seasons, and which is determined solely by the latitude of the country. New Zealand lies wholly within the Temperate Zone, and on the equatorial, or warmer, side of it. The amount of heat received from the sun is therefore never excessive even in the far north, while even in the middle of winter and in the southernmost portions, on the other hand, the sun rises high enough to give considerable warmth during the day. The difference in length between the longest and the shortest days in the year is about four and two-thirds hours in the northernmost and seven and one-third hours in the southernmost extremity of the Dominion. The day has never so short a length as eight hours.

If the surface of the globe were homogeneous—if, for instance, it were all ocean—all places on the same parallel would have the same climate, and there would be no need for any other classification than according to solar climate. Instead of this, however, we have a varying surface, some of it being land and some water, while the land surface varies in nature and in elevation. Solar radiation has very varying effects on these different types of surface, and they in turn react in different ways on the atmosphere. Based on these physical conditions, then, we have two main types of climate—viz., continental and marine. A marine climate is controlled to a large extent by the waters of the surrounding ocean areas, and, since New Zealand nowhere has any great breadth, its climate is of the marine type. The distinctive feature of such a climate is its sluggishness as regards temperature changes when compared with a continental one. When sunshine falls on a land surface most of it is absorbed in a very shallow layer and converted into heat. The surface, therefore, tends to become very hot. Water, on the other hand, reflects a large portion of the sun's heat back through the atmosphere, whence it is lost. Such radiation as is absorbed penetrates to a considerable depth, so that the rise of temperature at the surface is slight. Even then a good deal of the heat thus accumulated is expended in evaporating water. Over the ocean, therefore, there is very little difference in temperature between the coldest part of the day, just before sunrise, and the hottest, in the early afternoon. Over the land the difference is considerable, and increases, generally speaking, with the distance from the shore. Similarly, in a marine climate the difference between summer and winter is relatively small. Another effect of the sluggishness in temperature changes is that the seasons lag behind the movement of the sun. The spring is cold, although the days are getting longer and the sun higher and stronger. It is common knowledge in New Zealand that we are liable to cold snaps practically up to Christmas. Frosts damaging to vegetation are not rare in November, and snow storms occasionally affect comparatively low-lying country even later in the year. On the other hand, the autumn is warm, and mild temperatures may be experienced well into April. A marine climate is generally characterized by high average rainfall, its atmosphere being abundantly charged with moisture evaporated from the sea.

Generally speaking, then, the climate of New Zealand is equable, with an abundant precipitation, which is spread fairly uniformly over the different months. Not only is this so, but the difference in climate between the northern and southern extremities is comparatively slight in view of the fact that the Dominion covers a range of nearly 13 degrees, or about 900 miles, in latitude. The mean temperature at sea-level falls from about 62° F. in the far north to about 50° F. in the far south.

Another aspect from which there is an increasing tendency for geographers and meteorologists to classify climates is that of the vegetation produced by the soil. There are many plants which are able to live only within certain definite climatic limits, and others require certain restricted conditions to produce satisfactory growth. Since man depends so much for his livelihood on the products of the soil, the classification of climates on this basis is a logical and very useful one. From this point of view New Zealand has a warm-temperate and humid climate. The rainfall is almost everywhere sufficient for plant requirements all the year round. The temperature of 50° F. is an important one from the biological point of view, since many plants of the temperate region do not grow well unless the air rises above this temperature for considerable periods. Nowhere in New Zealand are there more than five months with a temperature lower than 50° F. In the Auckland Peninsula and in coastal places a little farther south, mean temperatures do not fall below 50° F. in any month. As regards the settled portion's of the Dominion, it is only in the elevated regions of Otago and Southland that the mean temperature fails slightly below 40° F. in some of the coldest months, or that the mean minimum for any month falls below freezing-point; consequently the ground is nowhere continuously frozen for long periods. Owing to these mild temperatures, there is some growth of herbage practically the whole year round. Vegetation has no long period of rest, and deciduous trees are practically unknown.

Since temperatures are everywhere warm enough to promote growth and nowhere excessively hot (the mean maximum for any month probably nowhere reaches as high as 80° F. or the mean temperature as high as 70° F.), there is comparatively little difference between the North and South as regards the nature of the things grown. Grapes, for instance, can be grown successfully out-of-doors in parts of all provinces of the Dominion. Certainly, in the North such semitropical products as citrus fruits can be grown successfully, whereas in the South this is not possible.

As regards human occupation, New Zealand lies in the zone of the Southern Hemisphere which is subject at all times of year to frequent moving barometric depressions, with all their accompanying weather changes. Some experts consider this an important condition for the development of civilization in its highest form. Cloudiness is nowhere excessive, so that there is plenty of sunshine, and a considerable range between day and night temperatures, which again tends to produce bracing conditions. Indeed, there can be few countries so admirably adapted for the production of a high yield from the soil and the maintenance of a high standard of comfort and civilization as New Zealand.

The Dominion is in the region of prevailing westerly winds. North of about New Plymouth and Napier these westerlies are not, in the main, strong, and, in fact, in summer there is a prevalence of south-easterlies. Though these can scarcely be classed as trade winds, even in the far north, they are to a large extent part of the same system. South from the 39th parallel of latitude the westerlies prevail, and although, in the free air at least, their mean strength increases the farther south we go, they are of considerable average force even in Taranaki and Hawke's Bay.

We next have to consider the feature that exercises the most potent influence in modifying climate in New Zealand—that is, its mountain ranges. Such variations of climate as are encountered in the different parts of the Dominion are produced mainly by these ranges. Their effect is closely associated with the prevalence of westerly winds. A range of mountains presents an obstacle to a wind which meets it. To force the air up and over it requires a great deal of energy. Wherever possible the wind will flow round rather than over. The most notable instances of this effect in New Zealand are found in the Cook and Foveaux Straits regions. Air in a westerly wind is forced round and over the lower portions of the northern part of the South Island into Cook Strait. Some of the air thus entering the strait possibly comes from as far south as Westport when the general wind is from due west. At the same time, the ranges in the North Island deflect into a southerly direction all winds which strike south of Cape Egmont. Some of the air is forced through the comparatively low gap in the neighbourhood of the Manawatu Gorge, while the greater part goes on down to Cook Strait. Similarly, in the south-west corner of the Dominion, a westerly wind is deflected into a north-westerly and flows round Puysegur Point into Foveaux Strait. A south-westerly wind is deflected into a westerly through the strait. The two regions mentioned are ones through which winds from a considerable area are forced to converge, and the consequence is that they are subject to an unusual proportion of strong winds. Through such channels it is practically only possible for winds to have one of two directions—i.e., they must blow through the straits from one direction or the other. Owing to the great preponderance of winds from a westerly quarter, the prevailing direction in Cook Strait is from the north-west. This wind may correspond with any direction between north-west and south-west in the open ocean waters where winds are unimpeded. More rarely there are strong winds from an easterly direction, which produce south-easterlies in the Strait. These may correspond with any wind between north-east and south over the open waters to the east. In the South the predominance of westerlies is greater than at Wellington, but there are at times strong easterlies through Foveaux Strait. Though not on the same scale, effects of a similar kind are noticeable in other parts. Round East Cape, for instance, there is a tendency for winds to be deflected along the coast-line, and easterly winds are likely to be specially strong there. At Nelson there is a different effect, and westerly winds tend to be deflected down Tasman Bay as south-westerlies, but at the mouth of the bay meet the winds which have come round Cape Farewell and are checked. Ifthe general wind, therefore, is between north-west and west-south-west about, the winds are usually light at Nelson.

When the general wind is almost due south-west, or practically parallel to the main range in both Islands, many parts of the Dominion are protected. Strong south-westerly winds may be blowing and wet weather prevail in the southern parts of Otago and Southland, and also in Taranaki and the northern parts of the Auckland Provincial District, while much of the rest of the country, including the inland portions of Otago, Canterbury, and Marlborough, the east coast of the North Island, and especially Cook Strait, experience unusually fine yet bracing weather and comparatively little wind. A slight deviation of this wind to one side or the other means bringing unsettled weather to the west coast of the South Island or to the eastern districts from East Cape southwards.

The checking of the westerly winds by the Southern Alps results in a large proportion of variable winds on the west coast of the South Island.

Although it is true that wind will flow round an obstacle in preference to climbing over it, yet when a broad belt of winds meets a mountain barrier lying across its path much of the air must be forced over the range. This happens when the prevailing winds, which are from between north-west and west, strike the Southern Alps, and, to a less extent, the ranges of the North Island. The distribution of rainfall over New Zealand is greatly influenced by this fact, as can be seen from the accompanying rainfall map. Most of our rain is produced from moisture carried from warmer latitudes by north-westerly winds. The rain falls either in the north-westerlies or when the latter are forced up by colder south-westerly winds. When the westerly or north-westerly winds are driven over the mountain ranges they rise into regions in which the air pressure is much reduced. They are, in consequence, cooled. The colder the air is, the less uncondensed water vapour can it contain. Moisture is therefore condensed, and falls as rain on the mountain tops and their western slopes. Generally speaking, therefore, districts with a westerly aspect have the heaviest rainfall. This is especially noticeable in the South Island, where the west coast opposite the Southern Alps has an excessive rainfall, while in their lee we have the driest areas in New Zealand, that in Central Otago being the most notable. Round Mount Egmont is another area of heavy precipitation. The East Cape district has a high rainfall because it gets a good deal of the northwesterly rain, and is also subject to very heavy falls in easterly winds which occur in connection with cyclones in the neighbourhood of the North Island.

When the westerly winds blow over the mountains they sometimes shoot down them again on the opposite side. Falling into levels where the pressure is higher they are heated, just as the air compressed in a bicycle pump is heated and warms the pump. Having lost a good deal of their moisture, they are very dry, and the energy gained by falling down the mountain slopes adds to their speed. We therefore have the gusty, hot, dry wind which is characteristic of mountain regions and is called the “Fohn” wind. The Canterbury Plains, especially the portions near the foothills of the Alps, form one of the regions of the world where the Föhn effect is most notably developed. The characteristics of the north-west wind are well known to the dwellers in these parts. During the Föhn wind a band of clear sky is produced on the leeward side of the mountains, while farther away cloud often forms again at a considerable height. This gives the characteristic appearance of the “Föhn arch.” Though most strongly developed in Canterbury, Föhn winds are experienced also in Otago, parts of Marlborough, and from the Wairarapa to Hawke's Bay.

Föhn winds, owing to their high temperature and to the fact that relatively high pressure tends to be produced in them on the west side of the ranges and relatively low on the cast side, are often underrun by east or north-cast winds on the east coast. These are especially prevalent in Canterbury, and the north-easter is a persistent and humid wind of an unpleasant type.

The shelter given from the ocean winds, and the clear dry atmosphere produced by the mountains, causes a nearer approach to continental conditions in their lee than in other parts of the country. The greatest extremes of temperatures are found in these regions.

In addition to the climatic effects above described, there are others produced by mountains and due directly to the elevation. Other things being equal, the amount of precipitation increases with elevation until about 5,000 ft. or 6,000 ft. is reached. Higher than that, it falls off again owing to the fact that the cold air above these levels is able to hold little moisture. Again, the greater the height above mean sea-level, the lower the mean temperature, the difference being about 3.5° F. per 1,000 ft. There are no closely settled areas in New Zealand sufficiently high for the elevation to produce any very marked influence on the climate. The effect is to some extent counterbalanced, too, in most places by the facts (1) that the sloping ground prevents the accumulation of cold air on the surface, so that night temperatures are less extreme than they might otherwise have been, and (2) that the atmosphere is more transparent, owing to the reduced amount of vapour it contains and the absence of dust, so that the sun seems to give more heat.

Above about 5,000 ft. snow frequently lies for long periods and the climate is severe. Forest trees become more and more stunted as this height is approached, and finally are unable to survive. Beyond it we have a mountain climate and characteristically alpine flora. The latter is adapted for resistance to drought, although actually the rainfall is usually heavy. The adaptation is necessary because of the rapid drainage, the intense heat produced on still clear days by the sun's rays, and the cutting off of water supplies from the roots for long periods owing to the freezing of the ground. Even in these high regions, however, conditions are not extreme. It is probably very rarely indeed that the temperature falls as low as 0° F., except perhaps for short intervals and in sheltered basins. The mountain region of the Southern Alps is, nevertheless, of great interest on account of its large and characteristic glaciers. The Franz Josef Glacier is especially famous, owing to the fact that it descends almost to sea-level, although the latitude is comparatively low. No doubt the very heavy rainfall on the mountains in this district and the rapid fall to sea-level are chiefly responsible for this effect.

The tables which follow, giving average values of various meteorological quantities for a number of typical stations, will serve to indicate the variation of climate in the different parts of New Zealand.

For comparisons with New Zealand conditions, data are given for Kew Observatory, near London, and for Aberdeen. It will be seen that even at Kew the mean temperature is lower than at Queenstown or Invercargill, while at Aberdeen the mean maximum is less than 2° F. higher than the mean temperature at these stations. Again, the number of days with rain is much higher at the British stations than in New Zealand for rainfall totals of corresponding amount. The Dominion also has a much larger average amount of bright sunshine. These advantages of increased warmth and sunshine, combined with an abundant supply of water, account for the wonderful fertility of our soil.