in the districts where those great fissures known as rakes occur, which are rich in minerals, especially lead, calamine, copper, gypsum, and fluor-spar. During the short period in which cave work has been taken up as a sport, discoveries have been made, which of course it is impossible to particularise, that may be the source of considerable profit in the future. The majority of those engaged in this physical exploration of caves are French. France possesses a Société de Spéléologie, the secretary of which, Monsieur E. A. Martel, author of _Les Abîmes_, is a most indefatigable and courageous explorer, and the man who has made the science an important and a living one. But M. Martel himself awards the title of "créateur de la spéléologie" to a forgotten predecessor, Dr. Adolphe Schmidl, who published _Die Grotten und Höhlen von Adelsberg_, in 1854. In this country, although such brilliant discoveries have been made of extinct animals and prehistoric relics of humanity, cave exploring of this kind is a new pursuit. M. Martel says, in _Irlande et Cavernes Anglaises_, 1897: "In short, the underground of the calcareous regions of the British Isles may be considered as being, topographically, very insufficiently known; this is the conviction impressed on me by my own researches in 1893." Something has been accomplished since that date. Two or three clubs, consisting chiefly of climbers, and a few speleologists working independently, have effected a thorough examination of the great caverns of the Peak, the extraordinary system of underground waters, huge cavities, and profound abysses in the West Riding, and the beautiful caverns of Somerset. But the ground that remains unexplored, the opportunities for adventure and the possibilities of discovery are such as may probably astonish those people who think there is nothing of the sort left in Old England.