I find on looking into the matter that it is true that there has, during the latter half of the past century, been a great dwindling of the lower end or “snout,” a drawing back, as it were, not only of Swiss glaciers, but of glaciers in other parts of the world--as, for instance, in Alaska and in the Himalayas. But I cannot avoid a feeling of satisfaction in recording the opinion of geological authorities that, contrary to the assertion of the Swiss pessimist, there is not any ground for believing that the present noticeable shrinking is due to a continuous process by which the enormous glaciers of remote ages have been incessantly reduced until now they are but rootlets or stumps of the former masses, destined to evaporate completely under the continued remorseless operation of increasing temperature. On the contrary, it appears that, though there are not accurate records and measurements as to past centuries as there will be as to present and future years, yet there is abundant evidence that Alpine glaciers have grown longer in some centuries and retreated in others. The period of alternate extension and retraction has not been ascertained with accuracy, but by some geologists it is supposed to be about fifty years. The retraction or shrinking is not due to a continuous increase of the temperature of the earth’s atmosphere--or of this hemisphere--but to contending causes which operate alternately towards increase and towards decrease when one or two hundred years are considered. Such are the greater or less rainfall and snowfall over a very large area, and the formation and persistence of clouds, concerned with which are probably those varying quantities--the spots on the sun. The simple proof that glaciers have extended and again retreated within historic times is furnished by the fact that in some parts of the Alpine range the retreat of a glacier has uncovered ancient miners’ excavations, which must have been worked when the glacier did not reach the spot excavated. Subsequently the glacier advanced, and now after some hundreds of years it has again retreated and exposed the ice-covered borings and workings. The tradition of a glacier-enclosed village in the Zermatt mountains, shut off from the world by the advance of glaciers, lost and mysterious, is evidence that such advance has been observed by the native population.