part of his holidays visiting a number of these ice caves, mainly in the Jura. Altogether he examined 14 or 15 caves personally, heard accounts of several more which he was unable to visit, and studied any accounts he could find in literature. His book, Ice-Caves of France and Switzerland was the result of his studies. After reviewing previous theories of the origin of subterranean ice, Browne came to the conclusion that the explanation was simple: provided that the chambers of the cave were below the level of the entrance, cold air would sink into the cave in the winter and be unable to escape; water in the cave would freeze, and would remain as ice provided that the interior was not exposed to direct solar radiation. He reported that all the caves which he had examined fulfilled these necessary conditions. Although Browne did not make detailed surveys, he gave some measurements, or at least estimates, of size, and described the interiors of the caves in careful detail, despite the fact that his lighting was very primitive – sometimes a candle, often just an oil lantern. He would resort to magnesium wire when large chambers had to be illuminated and he regularly provides sketches and plans or sections of some of these. Browne's descriptions of the caves, with the fantastic ice 'dripstone' formations to be found in some of them, are very vivid. The most entertaining parts of the book, however – and indeed the greater part of it – are devoted to his experiences reaching the caves themselves. Most of them are, or were in those days, far from a town of any size, and the privations endured were considerable. Although the recital of the difficulties of travel and of finding accommodation perhaps becomes a little repetitive, Browne writes with a graphic turn of phrase and gives a spirited idea of the problems of travelling off the beaten track in the 1860s. Food was often a problem, as, for instance, in the small town of Die in the Dauphiné, where the ravenous Browne, after rejecting various other offerings, faced up to the cold mutton, not withstanding the footprints of mice in the cold gravy, only to find that it was so strongly flavoured with garlic that he could not eat it. He was evidently a well-seasoned traveller, and some of the hardships, such as wearing wet clothes for days