THE NEW ZEALAND OFFICIAL YEAR-BOOK, 1927

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 those 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. Those 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, maintained at three ranges of temperature—viz., 104°, 106°, and 108° P. 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, those 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., 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 those 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 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 acute 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, &c., 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 an average of thirty thousand special treatments—massage, electrical therapy, &c.—is administered 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 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 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 northeastern 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. Although the immediate vicinity does not hold out much hope for its utilization, the rich agricultural districts which lie at some distance will no doubt rely on it in the near future as a convenient source of mechanical energy.

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-east 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 those 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 the Wairarapa Lake. 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 either small tarns high on the mountains or 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 Branner 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 the latter 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 which is 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 those 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.

These lakes are enormous reserves of energy awaiting development. Estimates of the amount available are somewhat uncertain in their upward limits, seeing that modifications of proposed schemes may increase the possible power to a marked extent. The only one, however, which has been utilized in an adequate manner up to the present is Lake Coleridge. This yields at present 16,000 horse-power (approximately), and if the scheme be developed to its full capacity the amount will probably reach 90,000. Lake Tekapo would furnish at least 400,000 horse-power; Pukaki, 70,000; Ohau, 100,000; Hawea, 90,000; Wakatipu, 100,000; Te Anau, 90,000; Manapouri, 420,000; and Hauroko, 80,000; and there are many lakes which could very easily be adapted for smaller installations. Especially is this the case in the fiord country, where the heavy and well-distributed rainfall produces an unfailing supply of water, where lakes are placed in ideal situations as reservoirs, and deep and secure harbours provide ample facilities for the transport of manufactured products. When these are properly utilized the now wild and deserted region will become the home of industry in the Dominion, and one of the main centres of manufacture in the Southern Hemisphere. One of these lakes—viz., Monowai, in Southland—is actually being utilized at the present time as a source of energy, and it is estimated to yield a minimum of 10,000 horse-power, with a maximum of 20,000.

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

Professor James Park writes: “Though so isolated, New Zealand contains within its narrow borders representatives of most of the Palæozoic, Mesozoic, and Cainozoic formations. Moreover, its structure is that usually associated with areas of continental dimensions; and for that reason it is often spoken of as an island of the continental type. It is a miniature continent; and the occurrence in its frame-work of thinogenic shore or shallow-water] rocks, ranging from the earliest geological epochs to the present day, is undeniable evidence that it stands on a subcrustal foundation of great stability.” (N.Z. Geological Survey Bulletin No. 23, p. 24, 1921.)

The oldest rooks in New Zealand appear to be those of western Otago, where over a large area is exposed a complex of gneisses and schists, intruded by granite and other igneous rocks. The gneisses in the main are altered granites and diorites, but some of the schists, at any rate, are of sedimentary origin. A pre-Cambrian age was assigned to these rocks by Professor F. W. Hutton, but Professor James Park considers them to be probably of Cambrian age, and includes them in his Dusky Sound Series, the lower part of the Manapouri System.

Perhaps next in age to the western Otago gneisses and schists are the mica, chlorite, and quartz schists of Central Otago. In the absence of fossils, however, the age of these rocks is uncertain. Professor Hutton regarded them as pre-Cambrian, Professor Park assigns a Cambrian age, whilst Dr. P. Marshall considers them to be little, if at all, older than the Triassic. Recent field-work by the Geological Survey, however, strongly suggests that an unconformity separates the Triassic rocks of the Nugget Point district from the greywackes of the Balclutha district, which overlie the Otago schists. In December, 1924, fossils of Permian (if not older) age were discovered near Clinton in greywacke and associated rocks. The horizon of these fossils is far above the schists, and therefore a pre-Permian age for the schists is undeniable. Some schistose rocks in north, central, and western Nelson may be as old as, or even older than, the Otago mica-schists. The gneisses and schists on the western side of the Southern Alps may for the present be classed with the Nelson schists.

The oldest known fossiliferous rocks in New Zealand are the Ordovician argillites (“slates”), greywackes, and quartzites occurring near Collingwood (Nelson), in the Mount Arthur district, and near Preservation Inlet in south-west Otago. Ordovicion rocks probably have a considerable development in other parts of Nelson and in Westland, but no recognizable fossils have been found in those areas.

Rocks containing Silurian fossils occur in the Mount Arthur, Baton River, and Reefton districts, Nelson. They are principally altered limestone, calcareous shale or argillite, sandstone, and quartzite.

Considerable areas have been assigned to the Devonian period by Mr. Alexander McKay, but owing to the non-discovery of recognizable fossils definite proof of age is wanting. For a similar reason the age of most of the rocks placed in the Carboniferous period (“Maitai Series”) by McKay is uncertain. At Reefton the supposed Carboniferous rocks, which here contain many auriferous quartz-veins, are almost certainly of Ordovician age. In the typical locality near Nelson the fossils found in the Maitai rocks, according to Dr. C. T. Trechmann, indicate a Permo-Carboniferous age.

So far Permian rocks have not been satisfactorily identified in New Zealand, but, as previously stated, fossiliferous strata of this age, or slightly older, have been found near Clinton, Otago. The Maitai rocks near Nelson ought probably to be classified as Permian rather than as Permo-Carboniferous. Park considers his Aorangi Series to be of Permian age.

During some of the Palæozoic periods it is conjectured that New Zealand formed part of or was the foreland of a large land-mass that extended far to the west. This land-mass possibly persisted to late Palæozoic times, and may have been the now dismembered and all-but-lost continent known to geologists as Gondwanaland.

Triassic and Jurassic rocks have been known to exist in New Zealand since Hochstetter's visit (1859), but the fossils were not extensively and accurately identified until the last decade, when Newell Arber and Trechmann published their valuable papers.

Newell Arber (1917) described an Upper Triassic flora from Mount Potts and Clent Hills (North Canterbury), and Hokonui Hills (Southland); Jurassic floras from North Canterbury and Southland; and a Lower Cretaceous flora from the neighbourhood of Oruarangi Point, south of Waikato South Head. Trechmann (1918 and 1923) examining marine molluscs and brachiopods from several localities, found that they ranged in age from Upper Triassic to Upper Jurassic, and correlated the different beds with European stages. The most fossiliferous localities are Hokonui Hills (Southland), near Nugget Point (Otago), Wairoa Valley (Nelson), Mokau watershed, Kawhia Harbour, and Waikato South Head, the three last-mentioned on or near the west coast of Auckland.

A broad belt of largely unfossiliferous but probable Trias-Jura rocks extends through western Canterbury and Marlborough, and is continued as a somewhat narrower belt on the north side of Cook Strait from Wellington to northern Hawke's Bay. Rocks of much the same appearance occur in the Lower Waikato Valley, in the Coromandel Peninsula, and in North Auckland. Some of these rocks may be of pre-Mesozoic age, but fossils to settle the point have not yet been found.

-No angular unconformity has been found between the Triassic and Jurassic, and the rocks have marked lithological similarity. Consequently the mapping of the boundary between these two systems is difficult, and, with our present knowledge, its extension into the great areas of unfossiliferous greywackes is impossible.

Cretaceous rocks occur at several points on the east coast of Otago and in central Canterbury. They extend in a not-quite-continuous belt from Cape Campbell in Marlborough to the neighbourhood of Waipara in North Canterbury. At Amuri Bluff they are richly fossiliferous. To the Cretaceous belongs a somewhat extensive belt of rocks near the east coast of Wellington and southern Hawke's Bay. A continuation of this belt extends from a point north-west of Gisborne to the East Cape district. In North Auckland Cretaceous rocks cover considerable areas.

The oldest known workable coal-seams in New Zealand occur in Cretaceous rocks. Much controversy, however, concerning the age of our coalfields has arisen. The late Sir James Hector, and with him Mr. Alexander McKay, considered that the coal-measures belonged to a Cretaceo-Tertiary system that extended from the Upper Cretaceous to the Middle Tertiary. For many years Mr. McKay was practically the sole exponent of this theory, but since 1911 Dr. Marshall has advocated a very similar view. The truth, however, seams to be that the coal-measures concerning which there is a dispute are of two different ages. The Kaitangata, Green Island, Shag Point, Malvern Hills, and Broken River (Canterbury) coalfields are probably of Upper Cretaceous age. The other coalfields, as mentioned below, are Tertiary.

To the Eocene may be assigned the coal-measures of the Taratu-Milton, Grey, Buller, and Collingwood districts, and some of the coal-bearing patches of central Nelson. In various other localities possible Eocene coal-measures occur. The Wangaloa beds, near Kaitangata, contain an Early Eocene fauna, which has also been identified at Boulder Hill, North Taieri, near Dunedin, and are underlain by the Taratu-Milton coal-measures.

During the Early Eocene, as some geologists and biologists believe, New Zealand was again part of a continental area that extended far to the north, and was joined, or all but joined, to New Guinea and northern Australia. This continent may have included much of the area in the Pacific now studded with coral islands. Its former existence is inferred mainly from various features in our plant and animal life. According to the late Mr. T. F. Cheeseman, no fewer than 366 New Zealand plants are found also in Australia, but recent botanical work tends to reduce the number. More significant, perhaps, is the occurrence of many closely related species and genera in the two regions, for comparatively few of the 366 species are likely to have persisted since the Eocene. Many of our birds show marked affinities to Australian and Malayan species. In this connection an interesting line of support for a Tertiary extension of New Zealand to the north is afforded by the annual migrations of the New Zealand cuckoos and of the godwit.

During the Oligocene and Miocene periods New Zealand subsided until little of the present land-surface was above water. Consequently, notwithstanding extensive denudation in later periods, Middle-Tertiary strata are well represented in almost all parts of the country. They are typically developed in the Oamaru district (northeast Otago), and hence Hutton's name of “Oamaru Series” is generally applied to the Oligocene-Miocene strata of New Zealand. There is reason to think, however, that the lowest part of the Oamaru Series is of pre-Oligocene age, but until patæonto-logical work now in progress is completed a definite opinion cannot be expressed. Oamaru rocks are well represented in South Canterbury, in North Westland, in North Auckland, and in many other localities. Brown coal usually occurs at the base of the Oamaru Series, and about its middle a fairly thick fossiliferous limestone is usually developed. This marks the time when the Middle Tertiary sea was deepest. Some of the finest agricultural districts in New Zealand are in areas where Middle-Tertiary rocks predominate.

The present tendency of the Geological Survey is to separate, under various local names, the uppermost Miocene strata from the Oamaru Series, even though this be held to include the Awamoa or Pareora beds. Strata high in the Miocene cover large areas in the North Taranaki, upper Wanganui, and Gisborne-East Cape districts, and are found also in Marlborough, North Canterbury, &c. In North Taranaki they contain valuable seams of brown coal.

In many localities the Miocene rocks pass without detectable angular unconformity into strata considered to be of Pliocene age. In the Hawke's Bay and Wanganui districts these are marine and highly fossiliferous. They give rise to much good agricultural and more especially pastoral land adapted to sheep-farming or dairying. In Nelson and north Westland the Pliocene strata are largely composed of river-transported material, and are known as the Moutere Gravels. These in places are poorly auriferous. In Nelson they form a poor pastoral soil, but one well adapted for apple-culture.

Towards the close of the Miocene and during the Pliocene period many parts of New Zealand, more particularly in the South Island, underwent elevation. As a result the North and South Islands (then quite different in outline from their present configuration), together with most of the outlying islands now in existence, such as the Chathams, Auckland Islands, &c., probably formed one large land-mass, which was united to, or almost reached, an Antarctic continent. Since many New Zealand plants^* are identical with, or closely allied to, South American forms, and there are also some striking resemblances in bird and other forms of animal life, some geologists and biologists believe that this Antarctic continent formed a bridge, though probably at no time quite complete, between New Zealand and South America. At the time of this continental extension the Southern Alps rose far above their present heights, and were covered with one vast snowfield that fed immense glaciers spreading far and wide over the lowlands to the east and the west. According to Park, during the Pleistocene a great sheet of ice spread over the whole of the present South Island and over part of the North Island. Moreover, this ice-sheet was joined to the Antarctic ice. The extreme views of Professor Park are not shared by other New Zealand geologists, who, however, unanimously agree that a large area in the South Island was glaciated. The great ice-streams of Pleistocene times gave rise to rivers that carried enormous quantities of gravel and finer material derived from the mountains beyond the ice-front, and in great measure built up the lowlands of Canterbury and Westland. In the latter district the gravels sorted by these streams-are in many places richly auriferous, but a greater and more permanent source of wealth is furnished by the fertile soil of the Canterbury Plains.

* According to T. F. Cheeseman's “Manual of the New Zealand Flora” (Preface, page xiv), 112 New Zealand plants extend to South America.

In many parts of Otago, Canterbury, Westland, and Nelson evidences of past glacial action are afforded by huge moraines, perched blocks, ice-worn surfaces (roches moutonnées), rock-benches, rock-basins, and other tokens of glaciation. To ice-action we owe some of the most magnificent features of the western Otago sounds. Some evidence of interglacial periods has been found, and doubtless more will be obtained by future investigations.

At or before the end of the Pleistocene period the mountains lessened in height, through both denudation and a well-marked subsidence of the land. The climate grew milder, and the lowland ice melted away. The mighty glaciers rapidly retreated, geologically speaking, and are to-day represented only by the comparatively modest valley and mountain glaciers of north-west Otago, Canterbury, and Westland, with which may be included the small but permanent snowfield and glacier on Mount Ruapehu. While the glaciers were retreating, the rivers of Canterbury and Westland, swollen by the melting ice, were unusually active in transporting debris to the lowlands and the sea-coast. At this time, too, as well as at somewhat earlier periods, the volcanoes of the North Island furnished an abundant supply of fragmentary material, much of which was transported by the streams and used in building plains and river-flats. Many of these are fertile, but in those districts where pumice abounded a poor soil, difficult of utilization, has resulted. Thus the land gradually became much as we see it now. In recent times geological changes, such as the lowering of heights by denudation, the filling of lakes by sediment, the outward growth of coastal plains in some places, and the wearing-away of the shores in other places, have slowly proceeded, and are to-day, of course, still going on. Slow movements of the land are probably in progress, but these have not been certainly detected. In 1855, however, as the result of a violent earthquake, the northern shore of Cook Strait, near Wellington Harbour, was raised on the average at least 5 ft., whilst the southern shore near Tory Channel and towards the mouth of the Wairau River was almost correspondingly depressed. The Taupo earthquakes of 1922 also caused a measurable movement of the land surface near Taupo.

In the preceding paragraphs little notice has been given to igneous rocks or to-volcanic action. The oldest igneous rocks of New Zealand are probably represented by the gneisses of western Otago, which, as previously stated, are mainly metamorphosed granites and diorites. Plutonic rocks intrude many of the Palæozoic and Mesozoic strata, and some of the formations also show evidence of contemporaneous volcanic action. Of the more ancient plutonic rocks granite is the most prominent. It occurs in many localities in Stewart Island, western Otago, Westland, and Nelson. It has, however, not been found in situ in the North Island, though in many localities boulders of granite and allied rocks, probably derived in all cases from ancient conglomerates, have been discovered. Ultra-basic igneous rocks, now largely altered to serpentine, occur in north-west Otago, Westland, Nelson, and to a minor extent in North Auckland.

Throughout the greater part of the Tertiary periods volcanic action in New Zealand was probably more intense than in any former age. During the Late Eocene or Early Miocene period eruptions, at first principally of andesitic rocks and later of rhyolite, began in the Coromandel Peninsula, and with brief intermissions-continued throughout Miocene and Pliocene times. These volcanic rocks contain the gold-silver veins which have been extensively worked at Coromandel, Thames, Waitekauri, Karangahake, and Waihi.

There are many areas of Miocene and later volcanic rocks in North Auckland, and near the City of Auckland numerous small volcanoes were in action during the Pleistocene, or even later. Some of these—for example, Mount Rangitoto—have possibly been active within the last few thousand years. In Taranaki the beautiful cone of Mount Egmont was built up during Pliocene and Pleistocene times. It is in the central part of the North Island, however, that the most intense volcanic activity has been displayed. Volcanic rocks, more especially the rhyolitic pumice ejected during the Pliocene and Pleistocene, cover large areas. Vulcanism has not yet ceased, for minor eruptions of fragmentary material still take place from Ngauruhoe, a typical volcanic cone near Mount Ruapehu. The most striking evidence of volcanic action, however, is afforded by the numerous steam-vents, hot springs, and geysers found in a belt extending from Ruapehu to White Island (in the Bay of Plenty), itself a volcano in the solfataric stage. It is more than a coincidence that this belt is in line with the Southern Alps. Solfataric action is generally regarded as a sign of dying vulcanism, but that the subterranean forces are still capable of mischief was shown by the eruption of Tarawera, an apparently extinct volcano, on the 10th June, 1886. On that occasion over a hundred lives were lost.

In the South Island vulcanism is apparently quite dead, for the hot springs of Hanmer Plains and the western side of the Alps are due to other causes. During the Miocene, however, volcanic outbursts took place in many localities, in some on a grand scale. Banks Peninsula is formed mainly of basaltic and andesitic rocks. Lyttelton and Akaroa Harbours are believed to represent ancient craters or centres of eruption. In the neighbourhood of Dunedin occurs a very interesting series of alkaline volcanic rocks. These were first described by the late Professor G. H. F. Ulrich, and in later years Dr. Marshall has given them much study. Recently alkaline volcanic rocks have been discovered in the outlying Chatham Islands.

In the course of a short article it is impossible to give any adequate idea of what has been accomplished by geological workers in New Zealand, or what remains yet to be done before even the foundation for future work shall be securely laid. The important applications of geology to agriculture and mining have hardly been mentioned, but elsewhere in this volume will be found descriptions of the agricultural and mineral resources of the Dominion. For detailed information the reader is referred to the bulletins of the New Zealand Geological Survey; to Professor Park's “The Geology of New Zealand,” which contains an excellent bibliography; and to the treatises on “Geology of New Zealand,” by Dr. P. Marshall, as well as to many other publications too numerous to be here named. Yet the “Transactions of the New Zealand Institute,” of which fifty-six volumes have been issued, must be mentioned, more especially since they contain many articles dealing with the palæontology and geology of New Zealand, as well as numerous papers on other branches of natural science. Finally it may be stated that in each of the University Colleges at Auckland, Wellington, Christchurch, and Dunedin excellent instruction in geology is being given by capable and enthusiastic teachers, so that progress in solving the many knotty problems of New Zealand geology is now being made, and may be expected to continue.

Since 1888 there has been established in New Zealand a system of observing local earthquakes at selected telegraph-stations—about eighty in number—distributed throughout the extent of the Dominion.

Whenever a shock occurs and is felt by an officer in charge of one of these stations he fills up a form giving the New Zealand mean time of the beginning of the shock, its apparent duration and direction, and the principal effects observed by him. Some of the officers exhibit considerable care and skill in making up these returns, and the data have been used to determine principal origins of earthquakes within the New Zealand region.

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

All observers of earthquakes are cordially invited to forward their reports to the Government Seismologist, Dominion Observatory, Wellington, giving all or any of the following particulars:—

The Rossi-Forel scale of earthquake intensities is as follows:—

Four seismographs, all with photographic registration, are installed in New Zealand: two are Milne horizontal pendulums, and two the new Milne-Shaw horizontal pendulums. One Milne and two Milne-Shaw seismographs are installed at the Dominion Observatory, Wellington, with their booms placed at right angles; and the other Milne seismograph is installed at the Magnetic Observatory, Christchurch.

A set of Wiechert seismographs with mechanical registration is installed at the Observatory at Apia, Samoa. By the courtesy of the Administrator copies of the records are forwarded to the Dominion Observatory.

One twin-boom Milne seismograph is installed at Suva, Fiji, and by the courtesy of the Government of Fiji the seismograms are forwarded to the Dominion Observatory. The Fiji records are useful in supplementing those of New Zealand.

The records of the New Zealand stations are sent to the General Secretary of the Seismological Committee of the British Association, to the Station Centrale Sismologique, Strasbourg, France, and to the principal observatories of the world, and thus form part of the general system of earthquake-observation being conducted throughout the world since 1890.

The accompanying diagram illustrates graphically the number and intensities of the earthquakes reported to the Seismologist in the years 1923, 1924, and 1925. These reports were supplied by officers of the Post and Telegraph Department, by private observers, and by the newspapers. Each vertical line represents the maximum effect of an earthquake, with the intensities according to the Rossi-Forel scale shown at the sides of the figure. It will be seen that one earthquake in 1925 reached intensity VIII on this scale, while two others in 1925 and one in 1924 reached intensity VII. The figure also shows the distribution in time of the earthquakes.

* A convenient means of verifying the time is provided by the wireless time-signals sent out every day, at 10.30 a.m. N.Z. time, by the Dominion Observatory on a wave-length of 600 metres.

Deaths due to earthquakes in New Zealand are fortunately very few. In the last seventy-five years seven have been recorded.

The shock of October, 1848, throw down a wall in Wellington, and three people were killed.

On the 24th January, 1855, a death occurred at Wellington recorded as “accidental death from the falling of a chimney.” The large earthquake took place during the night of the 23rd January, 1855.

On the 16th November, 1901, a child was killed by the Cheviot earthquake.

On the 12th April, 1913, a Maori was killed at Masterton by material falling from the post-office, due to an earthquake.

On the 7th October, 1914, a shepherd was killed by the Gisborne earthquake.

The climate of the Auckland Provincial District, speaking generally, combines degrees of warmth and humidity agreeable by day and comfortable by night. North of Auckland City conditions are almost subtropical, and in summer balmy easterly breezes prevail, and are responsible for delightful conditions. In winter the winds are more north and west, while changes to the south-west or south-east mostly account for the rainfall. Cumulus clouds are frequently formed in the afternoons, and, while tempering the heat of the day, also cut down sunshine records somewhat, but add considerably to the beauty of the land- and sea-scape. Southward of Auckland the climate is more varied, the west coast experiencing more rain, while the central parts are warmer in the day and considerably colder at night. In the winter months frosts, which are unknown farther north, now and then occur in the hours of darkness. Eastward from Rotorua (the great health resort and the centre of the thermal region) is to be found one of the most genial climates in the world, and Tauranga and Opotiki have charms all their own, especially for their weather and the fruits which ripen to perfection in these regions.

The monthly and annual means of the temperature, rainfall, and sunshine of Auckland and Rotorua are shown in the following tables:—

Hawke's Bay is one of the richest districts in New Zealand, and is favoured with a pleasant climate, being sheltered from westerly winds, though occasionally they are of the warm and dry (Foehn) type. It is rather dry, but ex-tropical disturbances are occasionally responsible for heavy downpours. Though the number of days with rain is less than, and sunshine above, that of other parts, the rainfall is still a good one, and fairly regular throughout the year, though some seasons have been notably dry. The meteorological records of Napier show reliable normals for the coastal districts. Inland the country is rather mountainous and less mild

As disclosed by its meteorological records, Wellington, the capital city, has a mean climate for the whole Dominion. Wellington occupies a central position, and is situated near Cook Strait, which divides the two main Islands. It has a somewhat changeable but temperate climate, and, though occasionally subject to disturbances from warmer regions, is usually controlled by the terrestrial wind-currents which have a westerly direction round the world in the latitude of the “forties.” It is popularly regarded as a rather windy spot, for high winds are frequently experienced, although they hardly ever reach hurricane force. Its windiness is largely owing to local configuration, for places quite near Wellington experience very little wind; and to compensate for this rather disagreeable element is a bountiful sunshine, averaging 2,017 hours per annum. There is a plentiful rainfall, amounting to nearly 50 in.

The region between Wellington and Taranaki, following the Taranaki Bight, is probably as fertile and agreeable as any in Australia or New Zealand; but inland, though very productive, conditions are not so favourable.

Taranaki has a rather heavy rainfall, and in most parts of this region the grass is always green. Its climate is mild, and cattle winter in the open. Wanganui and Manawatu districts (which lie between Wellington and Taranaki) have less rainfall than either Wellington or Taranaki.

It may be useful to make a comparison between the records of Wellington and those of Camden Square, London.

Nelson and Marlborough are highly favoured regions with regard to sunshine and shelter from marine winds. Long ago Bishop Selwyn said, “No one knows what the climate is till he has basked in the almost perpetual sunshine of Tasman's Gulf, with a frame braced and invigorated to the full enjoyment of heat by the wholesome frost or cool snowy breeze of the night before.”

Pastoral and agricultural industries are thriving, and Nelson is also famous for its fruit cultures—apples especially being celebrated for their variety, colour, and flavour. The rainfall about Nelson is very reliable, and averages from 35 in. to 45 in. per annum. Marlborough is also a sunny district, and its rainfall averages from 25 in. to 30 in.

Following are the rainfall and sunshine records for Blenheim:—

The climate of Westland is influenced by its position with regard to the prevailing westerly winds, its proximity to the sea from which these winds blow, and the mountainous character of its eastern half. The rainfall, as might be expected, is heavy, and ranges from about 70 in. per annum in the north on the coast to as much as 200 in. in the mountainous country. The weather-changes are chiefly due to atmospheric depressions, with lowest pressures passing south of the Dominion. Cyclones centred in the north, while bringing heavy rains to the North Island and the east-coast portions of the South, do not, as a rule, affect Westland, as easterly winds, which then prevail, are not conducive to cloud - formation in this district. Sunshine at Hokitika averages 1,925 hours a year, and, though not so abundant as in east-coast districts, this is a good average amount considering the rainfall. Westland is noted for a clear, beautiful atmosphere during fair-weather periods.

The chief health resort of the South Island, Hanmer Spa, is situated on a small plateau in the northern portion of the Canterbury Land District. On account of its altitude, 1,120 ft., it enjoys an invigorating climate, with a mean annual temperature of only about one degree below that of Christchurch. Owing to its elevated position and nearness to the mountains Hanmer is in some winter seasons subject to rather severe snowstorms, such as are never experienced on the Canterbury Plains. The mean annual rainfall is 40.82 in., and the mean total sunshine 1,990 hours

The district of Canterbury comprises a variety of topographical features. A plain stretches over a hundred miles from north-east to south-west, with a maximum width of about forty miles from the east coast to the foothills to the westward. The latter merge into the mountainous country culminating in the main range of the Southern Alps, which divides the provincial districts of Canterbury and Westland, and affords a protection from the heavily moisture-laden north-westerly winds. The rainfall of the Canterbury Plains is in consequence much restricted, the average being about 26 in. There is, however, a remarkable progressive increase from east to west, as is shown by the records. At Christchurch the mean is 25.30 in.; at Mount Torlesse Station (near Springfield), 40.24 in. The climate of Canterbury might almost be described as Con in type, with largo extremes of temperature between summer and winter and between day and night. Except in the three summer months frosts are numerous, and even in the early spring and late autumn they are at times severe enough to damage vegetation of a tender nature. In summer, day temperatures of over 90° in the shade are sometimes experienced. With regard to both climate and soil, the Plains have proved most suitable for agricultural farming, and much of the district is capable of growing splendid cereal and root crops. The prevailing winds in Canterbury are north-east and south-west, while north-westerlies are not as often supposed, of frequent occurrence. They are most common in the springtime, and, being dry and warm, they have a somewhat enervating effect, though in winter-time they come as a welcome change from the keen temperatures then generally ruling. The bright sunshine, as recorded at Lincoln, shows a daily average for the year of 5.7 hours.

Otago, the southernmost part of New Zealand, is very diversified as regards both its physical features and its climate. Inland, in Central and North Otago, the climate is dry and clear—hot in summer and cold in winter. The rainfall for this district averages from 13 in. to 20 in. Near the coast, in the Dunedin district, the rainfall in more plentiful, averaging from 30 in. to 40 in. per annum, a good deal of which falls in light drizzling rains.

There are continuous rainfall records from various parts of Dunedin for seventy years, of which the median rainfall is 33.5 in., and the mean in the table following may be regarded as too high.

The total rainfall for the year was below the average over most of the North Island and in the West Coast district northward of Greymouth and the extreme south of the South Island, while elsewhere it was above the average.

Following is a brief summary for each month of the weather and the chief atmospheric systems which were in evidence:—

January.—Several ex-tropical disturbances accounted for unsettled conditions from the 20th to the close of the month, and between the 25th and 27th some heavy rains occurred.

Rain also fell generally about the 12th, but the weather during the remainder of the month was, on the whole, warm and fair, and in the first half some high temperatures were recorded, particularly in the East Coast districts.

The rain about the 26th proved most beneficial to farmers and graziers in most parts of the Dominion.

Except in the East Coast districts of the North Island and parts of the Nelson and North Canterbury districts in the South, the total month's rainfall was below the average, and remarkably so in Otago.

Mean temperatures were mostly higher than usual, but there were cold snaps about the 11th, 17th, and 26th.

February.—During the first half of February most parts of the Dominion experienced fair weather, but the last half was dominated chiefly by westerly low-pressure areas which accounted for the prevalence of high westerly winds, unsettled, and, at times, stormy conditions.

Heavy rains occurred, especially in all the western districts and southern portion of the South Island. These parts recorded a total rainfall considerably above the average, while the east coast districts of both Islands experienced a deficiency, a reversal of the position in the previous month.

Conditions were particularly stormy about the 18th and 22nd, on both of which days the barometer fell very low in the South. The high winds caused much damage to fruit crops in various parts of the Dominion.

March.—In marked contrast to the same month last year, March proved one of the driest ever recorded, particularly in the East Coast districts. Rainfall was considerably below the average in all parts of the Dominion, with the exception of the high country and South Westland and Otago in the South Island and New Plymouth in the North Island.

During the first fortnight the weather was changeable, with squally and showery conditions, especially in the West Coast and southern districts. An anticyclone then ruled until the 25th with fair weather generally. The latter part of the month was somewhat unsettled, but, on the whole, the weather during the month was dry and sunny, with warm days and cool nights.

On the last two days sharp frosts occurred in many places.

April.—April proved a fine, dry, and sunny month on the whole, with rainfall generally below the average. In parts of Canterbury, however, the total was in excess, and considerably so at places about Bank's Peninsula. This is accounted for by a particularly heavy downpour on the 16th, which resulted from a cyclonic disturbance passing between the 15th and 19th and which intensified when located off the east coast. The east coast of the North Island was not affected by this storm, the aggregate rainfall in that district showing the greatest percentage below normal for the whole of the Dominion during April, Napier having only 8 per cent. of its mean precipitation.

Except during the period when the above-mentioned cyclone ruled, and also between the 5th and 8th when a rather intense westerly low-pressure area was in evidence, atmospheric pressure was usually above normal.

May.—During May the most remarkable meteorological feature was the number of cyclonic disturbances which passed in the North. On this account rainfall was greatly in excess of the average over the North Island and in the east-coast portions of the South Island, and deficient in the western and southernmost districts of the South.

There were two periods when fair weather prevailed over the Dominion as a whole —viz., between the 7th and 11th and the 24th and 28th; but during the remainder of the month, except in Westland and Otago, unsettled and wet weather predominated.

Heavy rains and floods occurred in the northern districts about the 12th, 14th, and 15th, and very stormy conditions were experienced over the Dominion on the 22nd and 23rd, with further floods in the North. Both these stormy periods resulted from ex-tropical cyclones, and an intense cyclone also made the close of the month extremely unpleasant for the northern districts.

June.—The weather in June was dominated by similar conditions to those experienced in May, there being again a remarkable prevalence of ex-tropical disturbances. The latter chiefly affected the North Island and the north-east districts of the South, and, in consequence, these parts received a rainfall considerably above the average, while in South Canterbury, Otago, and Westland fair weather predominated, with a low rainfall.

Except for a period of anticyclonic conditions and fine weather between the 11th and 22nd, the weather was extremely unsettled and, at times, stormy. During the last week, owing to abnormal rains large areas of country in the northern districts were flooded, and on the last three days snow fell in many parts of the South Island.

July.—The stormy conditions which were prevalent during the last week of June continued into July until the 10th, heavy rains and floods being experienced in the northern and East Coast districts. The Canterbury rivers also flooded, owing to the warm rains melting the recently fallen snow in the higher country.

Unsettled and wet weather also ruled between the 13th and 16th and the 21st and 25th. During the latter period an extensive disturbance held sway, with very low pressure in the South, and beneficial rains fell in Otago, where extremely dry weather had been experienced for some time.

Anticyclonic conditions and fair weather prevailed generally between the 10th and 13th, the 17th and 19th, and from the 26th to the close of the month.

The total rainfall was above the mean in the Bay of Plenty, Hawke's Bay, and Taranaki districts in the North Island, and in Westland and Canterbury in the South Island. Auckland and Wellington districts, as well as parts of Otago and the central portion of the South Island, recorded a deficiency.

On the whole, the weather proved dull, mild, and humid, and in most parts of the Dominion there was more than the usual growth of grass for the time of the year.

August.—August proved a dull and wet month in most parts of the country, the East Coast districts especially having a total rainfall considerably in excess of the average. The Auckland and Taranaki Provinces in the North Island, and the country about Westport, Greymouth, and Foveaux Strait in the South, had a deficiency. Westland, owing to a prevalence of east to south-east winds, appears to have experienced the greatest number of fine days.

A storm of somewhat local character occurred in Canterbury on the 6th and 7th, with heavy rain, snow, and bleak weather. A cyclone passed in the North between the 12th and 15th, accounting for high east to south-east winds and some heavy downpours. Anticyclonic conditions followed, and the highest reading of the barometer, 30.675 inches, was registered at Wellington on the morning of the 17th.

An intense westerly disturbance passed in the South, with a barometer reading of 28.95 inches, at the Bluff, on the 23rd, and was preceded and followed by very unsettled weather. Snow, hail, and thunderstorms were reported at various times on high country of the South, and some sleet at lower levels.

The wet weather was a great hindrance to farming operations in Canterbury, and growth of grass was delayed by several frosts and dull weather in many other parts of the country.

September.—The weather during September was, on the whole, unsettled, bleak, and squally. Westerly disturbances predominated, and were usually of considerable extent and intensity. Rainfall was therefore above the average in districts having a westerly aspect, and deficient at most places on the east coast of both islands.

Stormy weather prevailed generally between the 3rd and 8th, and during this period some heavy snowfalls were experienced in the South Island. Conditions were also severe from the 19th to the 27th, very heavy rains accounting for flooded rivers in Westland about this time.

The month was an extremely unfavourable one for agricultural and pastoral pursuits, and vegetable growth was very backward on account of the cold and lack of sunshine.

October.—October's weather was an improvement on that experienced in the preceding spring and winter months, less wind and more continued warmth being favourable to vegetable growth and stock.

Although westerly disturbances predominated, only one, which passed in the South between the 13th and 15th, was of marked intensity, causing strong northerly to westerly winds and considerable rain, especially in the South and about Cook Strait.

Anticyclonic conditions ruled during the last week, when fine sunny days and cold nights were experienced generally.

The total month's rainfall was below the average in all districts, except Nelson and parts of Otago in the South Island, and about the Bay of Islands in the North.

November.—As in the preceding month, weather conditions during November were chiefly affected by westerly disturbances, with lowest pressure southward of New Zealand, and northerly to westerly winds predominated. Southerly changes, however, occurred on several occasions, and, though of brief duration, they were very marked, and were in parts accompanied by hail and sleet, and followed by frosts.

Two disturbances intensified considerably after passing to the eastward, and accounted for severe southerly gales on the 16th and 26th, with cold squally conditions, particularly along the east coast.

The aggregate rainfall for the month was mostly below the mean of previous years, but above along the east coast of the South Island southward of Kaikoura and in Westland.

On the whole, the weather, though somewhat changeable, was warm, dry, and windy.

December.—Warm, dry, and windy weather was experienced during December in most parts of the Dominion and, except in Westland and the high country of the South Island, the aggregate month's rainfall was everywhere below the mean. The latter districts had more than their average precipitation, chiefly owing to two severe westerly storms, one which ruled on the 3rd and 4th, and the other between the 9th and 11th. The heavy rains during these two periods caused floods in the West Coast rivers, and also, at the same time, some of the Canterbury rivers flooded, owing to the melting of the snow on the eastern slopes of the Southern Alps.

There were several other minor westerly disturbances during the month, and only one ex-tropical “low,” which passed too far north to benefit Hawke's Bay. A thunderstorm there, however, on. New Year's Eve, brought some temporary relief from an extended period of drought.

The following tables show the difference, above or below the mean, for each month in the year:—