Meteorology. The Ideal Weather Station.

Progress, Volume V, Issue 6, 1 April 1910, Page 200

Meteorology.

The Ideal Weather Station.

Mount Egmont, Taranaki. (('OiUinucd.) (E. Barton, Brisbane.) During the ascent on that part of the mountain known as> "The Lizard," the effect of this, method of disintegration is particularly visible, large blocks of lava being seen in every stage of detachment from the main mass The action of the frost is assisted by the preence of dust blown from the surface of the scoria, which gradually fills up the interstices as they become enlarged by the frost. "Did you find much difficulty in attaining the summit of the mountain." I failed twice in attempts made from the Falls House, once owing to a fog and the second time owing to the piercing wind. My next attempt was from Egmont House, and my party, which included two ladies, had no difficulty in reaching the top. The only requisites for success are fine ■weather and determination. At the same time, I would advise those who are unac(ustomed to great exertion to take the mountain gently. We started at 5 a m., and after four rests of an hour each we reached the summit at 2.30 p.m. I carried provisions for the party of three, and some instruments (total weight 201b.) in a knapsack. I mention these details because the ascent is usually made 100 hurriedly to allow of enjoyment by persons of mature a ears or by ladies. "Is there no need of skill with the ice axe and the alpenstock?" Not m the ascent from ' ' Egmont House, ' ' \\ hich is made over scoria and rock, and calls for no such skill. A little knowledge of the use of the alpenstock and the ice axe certainly adds greatly to the interest and pleasure, because the steep slopes of virgin snow, which, cover most of the scoria during the early summer, give an opportunity for many an exciting "glissade" during the descent if the tourist is possessed of a little nerve. On the occasion of my descent the party indulged in a few "glissades," which uere very exhilarating, but would have been impossible "without alpenstocks. The first essential in "glissade" work is to realise that the sliding is done on ice, although apparently on snow. Pure snow does not lend itself readily to a glissade, unless snow shoes or "ski" are used to prevent the feet from penetrating the soft and yielding material; but on snow which has thawed on the surface and has then frozen again no such support is needed. The ice skin which is formed thereby is smooth and slippery, but easily pierced by the point of the "alpenstock," Avhich is a light, strong stick about 6ft. in length, shod with a sharp iron ferrule and provided at its upper end with a leather wrist thong oi an enlarged knob. In ascending a mountain, the alpenstock is of little value until the snow is encountered, but in descending the mountain it is in constant use, being used as a prop in advance of the body. During a glissade the weight of the body is thrown back on the alpenstock while one

slides in a standing or squatting position. It is important to maintain the upright position, because the loss of balance brings one into a sitting position, where the alpenstock loses its braking power, and then the speed of descent may become alarming. ' ' Would you not have enjoyed Mt Egmont better in autumn, with more settled leather?" Certainly the ascent would have been easier, because Mt. Egmont can be climbed from either side with ease during the month of March, but, with the snow, half the beauty of the mountain has departed. The graceful curved slopes of frozen snow no longer set off the bareness of the lava and scoria, while the drier autumn atmosphere no longer supplies the material for the beautiful cloud effects The ideal t'me for ascending Mt Egmont is the Christma stide. Those who love the excitement of ice-axe work will then m ike the ascent on the southern side from the Falls House The high winds, generally prevalent near the summit, however, cause a sense of insecurity whilst passing from one ice step to another which is too alarming for the ordinary tourist, and he will do better from "Eermont House." One of the most interesting features of the mountain is the regular decrease in the size of the trees and plants as the snow line is approached. On entering the forest reserve one is struck with the gigantic size of the flowering Rata, with its beautiful red blossom, and with the almost tropical appearance of the lianas and parasitic growths, which remind one of North Queensland. As the ascent is made the trees become more stunted in size, the tree fern disappears, while the moss on the tree stems turns from a deep green to a light grey colour. Presently the shrubs are left behind, and only grass tussocks and moss are to be seen. At a height of 5000 feet the moss and the lichens are the only signs of plant life. After leaving the moss, long ridges of scoria are encountered, which consist of innumerable stones varying from boulders down to minute particles of black obsidian and crumbled pumice, which lie at an angl^ of 30 degrees, and therefore give way under the feet and lead to great weariness on the part of the climber. With patient toil he at last reaches the lava dyke known as the "Lizard." His progress is now much easier, because he gets a solid foothold on the rock, although the steepness has increased to 40 degrees. The track all the way from the Mountain House to the top lies on ridges, and nowhere passes through the valleys, which are deep gorges, terminating in abrupt faces of lava quite inaccessible to the ordinary climber. All the ridges gradually converge towards the top, so that it is scarcely possible to lose the way while ascending. In fact, on a clear day the danger of losing the road seems ridiculous ; but on the descent, where every ridge forks out into several ridges, the way is readily lost, even during fine weather. The chief risk arises, however, from the liability to sudden envelopment in mountain mist. At any moment an ascending column of warm air may creep up the side of the mountain and form a cloud, which from the plain appears like a wisp of smoke, but to the person immersed in it, produces the effect of blotting out the whole world as though with the legendary "cap of invisibility.." In such, cases an inexpensive

pocket compass is, a great comfort to the climber who has a good map. The available maps o£ Mount Egmont are large and pretentious, but of a very poor type, the lava ridges, watercourses and mountain tracks being only approximately given. The maps in Baedeker's handbook of Switzerland might well be taken as a standard for future editions. Pursuing his way up the "Lizard," between two steep slopes of snow, the tourist comes at last to a point whore the mass of rock forming the Lizard's head blocks his way. Now he has to leave the lava ridge and finish the journey on the gently sloping surface of the snow field forming the lip of the crater, Avhich is filled with snow, s-o as to appear like a smooth white bowl. It is surrounded by a crown of jagged pinnacles, between which the inner and outer slopes of snow unite in beautiful sweeping curves of dazzling whiteness. From the centre of the crater the pinnacles can be ascended by scrambling up the hard frozen surface of snow, using the alpenstock or ice axe to form little steps. I shall never forget the glee of my party on observing that the interior of every hole made in the snow was blue, the depth of colour increasing with the depth of the hole. We would gladly have stayed for hours at the top enjoying the wonderful view, but the piercing cold drove us down, although the temperature, according to a shaded thermometer, was eleven degrees above freezing point. The frozen condition of the surface of the snow proved, however, that the effect of radiation was more important than the actual temperature of the air. While ascending the mountain I had the pleasure of observing some very interesting weather phenomena. The wind was coming in from the south-west, from the Taxman Sea, over which scarcely a cloud was visible, but the land was hidden under a closely packed layer of clouds, which had the appearance of a white tesselated pavement, the individual tesserae being separate clouds, with narrow spaces between them. This white floor spread round each side of the mountain, and then extended inland and along the coast in two great streams, one stream sweeping down to Cook's Straits and following accurately the bend of the outline of the coast past Wanganui, and the other following the coast line to the North passed Kawhia, and it extended inland to the foot of Ruapehu, Tongariro and Ngauruhoe. but left in the wake of the mountain a narrow space almost devoid of cloud. Through this rift could be seen, at intervals, the towns of Stratford, Eltham and Ingle wood, but they appeared very dark in contrast with the dazzling white cloud surface and indistinct of outline, owing to the existence of a heavy haze between the ground and the cloud level. Above the cloud no haze was visible. On the mountain the velocity of the wind was about 20 miles per hour, but at the height of the clouds (about 2000 ft.) the air was moving at barely 4 miles per hour. Wherever this moving mass of clouds met a considerable obstruction, such as a headland or small mountain, it behaved as a torrent would to a submerged rock; a stationary wave was formed. This was particularly noticeable over the headlands of Waitara and Kawhia, and over the ranges near Palmerston. The great mountains such as ftuapehu stood up 6000 or 8000 feet above

the clouds, which there resembled waves dashing against a coastline, the clouds breaking into spray as they slowly rose on the nanksi of the mountains. The view was marvellously fine. "What was the most striking feature at the summit?" Three things struck me with astonishment. The first was the apparent height of the horizon. Owing to the position of the mountain on a promontory, the sea is visible on three sides to a distance exceeding 100 miles On three sides, although the horizon was really 15 000 ft below the plane of the mountain top it appeared to be on a level with us. Thus we appeared to be in the centre of a blue bowl 200 miles in diameter and 8000 Peet deep. The second was the colour of the sky overhead which was no longer "sky blue" as when viewed from the plain, but a deep violet colour. The third was the presence of blowflies, which apparently find their habitat in such altitudes The supply seemed inexhaustible, because I killed all that I could see at one time, and in ten minutes their ranks were replenished. "As a meteorologist, what do yon think of Ihe mountain"? It seemed to me an ideal place for an observatory, being nine time? the height of the Eiffel Towel, and almost as free to the movements of the air During most of the bad weather it must bo above the clouds, and an observatory placed at the summit and connected, as m the ca^e of the "Sonnblick" observatory, bv telephone with the plain, would give information concerning temperature barometri" pressure, and humidity, and concerning movements of cirrus clouds and winds valuable for daily forecast work, but indispensible for the future development of seasonal forecasts. "Prom tho summit the weather workshop of nature seemed exposed to view. In the distance great columns of bush-fire smoke Avcre seen. One of these arose from the Wanganui valley, and was particularly interesting. The smoke rose almost vertically to a height of 4000 feet. It then entered a stratum of air where a strong N.W. prevailed, and became deflected towards the south-east for a distance of about 40 miles, being extended into a long thin horizontal streamer, owing to the greater velocity of the wind at that level. On reaching a point some 20 or 30 miles, southwest of Ruapehu, it became deflected towards the north-east, and when last observed, as the sun was setting, it disappeared behind Tongariro. During another ascent the top of the mountain presented a beautiful phenomenon which, for the want of a better name, I shall call the "Bridal Veil." It consisted of a thin cloud, and had the appearance of an enormous crystal bowl balanced like a hat on the top of the mountain. A curious feature of the Veil was that it was in two distinct layers separated from each other by space of 30 feet. It was evidently the result of an upward deflection of two moist layers of air passing over the summit of the mountain. As is well known, the chief cause of formation of cloud is the chilling effect of expansion. This effect is well known in the production of cold by refrigerating machinery of the type invented by Haslam, where the expansion of the air is utilised

to produce cold, but where considerable trouble is met with in the shape of condensation in the valves and ducts through which the expanding air flows. In the case of our atmosphere, the expansion is brought about by an upward movement of the air, the resulting cold producing precipitation of moisture. Although the sea wind, on striking an isolated mountain such as Egmont, is not raised bodily, and therefore does not give such an extraordinary precipitation as nn the slopes of the New Zealand Alps, which take all the moisture out of a N.W. wind and let it fall into Canterbury in a dessicated condition. Yet on the seaward slopes of Egmont the streams are larger than on the other side, and the "Falls Tlou^e" on the southern side is surrounded by gushing streams, and has an abundant supply of water, while the "Egmont Tlonse" on the N.E. side has to rely on storage tanks. If Egmont was beautiful during the daytime, it also had charms at night One calm moonlight night I saw it covered with a robe of vapour so complete and so wellfitting as to appear like a coating of snow from the summit down to the forest line. Observing the air to be descending from the summit I concluded that this effect was caused by the cooling effect of the snow on tbe layer of air which lay in contact with it This chilled skin of air, coming from aloft, would be too dry to permit of condensation of its own vapours, but, by contact with the next outer layer of ord'nary moisture-carrying air, would cause condensation at the surface of contact between the two, and would account for this beautiful phenomenon. It is to the meteorologist that Mount Egmont appeals mo«t strongly, and months could be spent profitably in making observations on its flanks, especially Avith regard to the accumulation of data concerning the physical properties of our atmosphere in its upper strata, the line of investigation which in most countries is carried on by means of kites and small balloons. For such purposes I <>m importing into Queensland a number of India-rubber balloons, such as are used at Trappes, in France, by M. Teisserene de Bort, where they are released, and ascend to a height of 20,000 or 30,000 feet, carrying registering instruments to record the various conditions of the air in the layer traversed during the upAvard movement, until the balloon bursts, and then during its doAvnAvard movement until it strikes the earth. Unfortunately many of these balloons are lost, and records never come to light. At Blue Hill, near" Boston, under a Mr. Lawrence Rotch, and in many observatories Avhich have carried his methods, kites are used for the purpose of raising instruments, but in this case the height attained rarely exceeds that of Mount Egmont, and the records are necessarily disjointed, owing to the varying height at which the kite will fly at different times during the experiment. If the earth were only girdled with a complete series of such observatories, we might expect in a very few years to obtain reliable seasonal forecasts. The enormous financial value to the primary industries, both pastoral and agricultural, of such foreknowledge is incalculable, but for Australia alone would probably exceed ten million yearly. But there is no industry-

or business which would not be effected by such knowledge. From the draper who, in fear and trembling, orders next summer's goods, to the Steamship Company, which organises excursions, to the Sounds. When we see the large expenditure incurred by the State for superfluous officials, one is filled with regret that some of these rivers of money could not be diverted into channels of important scientific investigation such as "weather law." At present Germany and Austria are the only countries which have made liberal provisions for this science, their annual expen dilure exceeding that of all other nations put together.