SOUNDS AND GLACIERS.

Timaru Herald, Volume XIIC, Issue 13957, 17 July 1909, Page 3

SOUNDS AND GLACIERS.

DESCRIBED AND ILLUSTRATED A numerous company of old _ and young, but by no means filling Trinity Hall, assembled last night to listen to a most instructive ami interesting lecture on Sounds and Glaciers, by Professor Marshall, of Dunedin University. Mr R. H. Rockel, presiding, in introducing the lecturer, made a few remarks on the change which had taken place in the teaching of geography in schools, the greater attention now bestowed on physical geography being much more sensible than the learning of strings of names. As yet there was comparatively too much attention paid to the physical geography of other countries, too little to that of New Zealand.

- Professor Marshall in his opening remarks, said .that New Zealand • was remarkable for the great variety of its topographical features, a numoer of classes of which he mentioned. After humorously pointing out the limiting conditions of a popular-scientific lecture, he took his audience by ear and eye about the summit of Ruapehu, with its ice-cliff, about a hot lake in the crater, and then showed fine views of the Tasman and Upper Rangitata Valleys, to show the action of glacier ice where it is in operation to-day, with, especial reference to the kind of valleys the glaciers carve out of the__ mountains — deep valleys by the niaih ice streams shallower by their tributaries. The difficulty of ascertaining the depth of glaciers was explained; but assuming the condition to be. somewhat similar, to those of the Aar in Switzerland, the depth of the Tasman glacier a few miles from its terminal face was prooablv 2500 feet. If then the glacier were to melt away, there would be seen a rock-basin with vertical walls 2500 feet high. And the tributary glaciers, now flowing -in shallower streams of ice at the level of the main stream, would leave "hanging valleys," from which the rain water would reach the main valley by waterfalls over liigh precipices. After this introductory- glance through Nature's workshoo.' where the glacier rasp and file are still cutting away the bottom of every valley, it was easy to understand the description and very fine views of the grand valleys of the Sounds, their clond-high precipitous bare-rock sides, and as precipitous descent beneath the salt water. The rounded, smoothed, and polished rock surfaces characteristic of glaciated areas were also found plentifnllv about the Sounds, and a\? together "the appearances they present prove that the Sounds are huge ice-cut valleys. The Sounds of Marlborough were" also illustrated by a specimen picture or two, and explained as having originated by the submergence ot stream-out, not glacie-cut, valleys. This led to some remarks on the mStabilitv of the surface of the earth, which in geological time is subject to verv great changes of level indeed. A talk about the depth of Lake Wakati'pn 12S0 at its deepest, led to a dissertation on the scooping _ power ot glaciers, when of great thickness; as was the glacier which scooped out this like The this great glaoiation"of New Zealand, Professor Marshall put„at 150,000 years ago—quite

a recent date in geology—and at that period all lands in the southern hemisphere down to the same latitude were glaciated. In Western Europe and in North America the great ice descended to still lower latitudes. Several theories of the cause of ice ages were briefly described, and the conclusion of it all was: "We do not know."

The lecturer having consented to answer questions, a few were asked by members of the audience and courteously answered. The Rev. T. Stinson supplied and managed the lantern, and a most interesting collection of views were well shown.

Messrs A. Bell and T. D. Young proposed a hearty vote of thanks which was carried by acclamation and suitably acknowledged^