Page:Popular Science Monthly Volume 17.djvu/214

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THE POPULAR SCIENCE MONTHLY.

in Fig. 3: the fossil has been broken up, and its pieces have been more or less separated from each other, exactly as in the natural examples.

By pursuing a similar line of research, M. Daubrée has succeeded in imitating a characteristic feature of the structure of large chains of

Fig. 2.Belemnites niger, B, closely inclosed by costing in the center of a prism of lead: in two parts, only one of which is represented. The prism is to be subjected to the action of the hydraulic press perpendicularly to its larger sides. (Scale of one half.)

mountains, which Saussure observed on Mont Blanc. The masonry-work of Mont Blanc, says this author, is divided into great leaves having their planes exactly parallel to each other, and parallel to the direction of the chain. He further satisfied himself that the leaves,

Fig. 3.—Stretching out and truncation of the belemnite of the preceding figure by the action of the hydraulic press on the prism of lead in which it was incased.

nearly vertical in the center of the mass, assumed inclined positions in their lateral parts, and dipped symmetrically toward the central axis, so as to present in their transverse section the form of a half-opened fan. Little Mont Blancs can be reproduced in miniature, with a structure like that described by Saussure, in this way: Take clay which has been previously well mixed and nearly dried, and cut into the form of a square prism; and, having put it between two square plates of the same dimensions as the base of the prism, subject it to the action of the hydraulic press. In the operation a beard (bavure) or overflow runs out from each of the four-lateral faces, the expanding form of