Probably every mountain climber, resting for a brief space on a loose boulder, or seeking the shade of some overhanging piece of rock, has often asked himself, "How were all these rocks made?" The question must occur again and again to any intelligent person on visiting a mountain for the first time, or even on seeing a mountain-range in the distance. He may well ask his companions how these great ramparts of the earth were built up. But unless he possesses some knowledge of the science of geology, which tells of the manifold changes which in former ages have taken place on the earth, or unless, in the absence of such knowledge, he chance to meet with a geologist, his question probably remains unanswered. Such questions, however, can be very satisfactorily answered,--thanks to the labours of zealous seekers after truth, who have given the best part of their lives to studying the rocks which are found everywhere on the surface of the earth, and the changes they undergo. Geology is a truly English science; and Englishmen may well cherish gratefully the memories of its pioneers,--Hutton, Playfair, Lyell, and others, who have made the way so clear for future explorers. The story of the hills as written on their own rocky tablets and on the very boulders lying loose on their sloping sides, and interpreted by geologists, is a long one; for it takes us far back into the dim ages of the past, and like the fashionable novel, may be divided into three parts, or volumes. To those who follow the stony science it is quite as fascinating as a modern romance, and a great deal more wonderful, thus illustrating the force of the old saying, "Truth is stranger than fiction." The three parts of our story may be best expressed by the three following inquiries: I. How were the materials of which mountains are built up brought together and made into hard rock? II. How were they raised up into the elevated positions in which we now find them? III. How were they carved out into all their wonderful and beautiful features of crag and precipice, peaks and passes?