Page:Popular Science Monthly Volume 48.djvu/466

This page has been proofread, but needs to be validated.

Seeley, H. C The Story of the Earth. New York: D. Appleton & Co. Pp. 186. 40 cents.

Shaler, Nathaniel Southgate. Domesticated Animals. New York: Charles Scribner's Sons. Pp. 267. $2.50.

Simeon, James. Discussions on the Gypsies, and Do Snakes Swallow their Young? Pp. 123. And The Social Emancipation of the Gypsies. Pp. 24. New York: Printed by E. O. Jenkins.

Snyder, Charles Porter. The New Cosmology. Published by the author. Pp. 16.

Stanley, William Ford. Notes on the Nebular Theory. London: Kegan Paul, Trench, Trübner & Co. Pp. 257. 9s.

Stedman, Thomas L. Twentieth Century Practice. An International Encyclopædia of Modern Medical Science in Twenty Volumes. New York: William Wood & Co. Vol. IV. Pp. 841.

Tarr, Ralph S. Elementary Physical Geography. New York and London: Macmillan & Co. Pp. 488. $1.40.

Vulté, H. T., and Neustadt, George M. S. Laboratory Manual of Inorganic Preparations. New York: George Gottsberger Peck. Pp. 180. $2.

Weekly Review, The. (Educational Periodical.) Ann Arbor, Mich.: Published by the Cooperative Educational Association. Vol. I, No. 1. Pp. 24. $2 a year; 5 cents a copy.

Fragments of Science.

A Device for Geological Teaching.—It is now six years since there was issued a small edition of an educational appliance invented by James T. B. Ives, F. G. S., and appropriately named by him the Strata Map. Since that time the inventor has made various improvements, and is now bringing out his map in a more completely satisfactory form than heretofore. Hanging on the wall it appears as a geological map of the United States, east of Denver, in the ten colors recommended by the International Congress of Geologists for the coloration of geological maps. On touching the fastening at the upper edge of the frame, the glazed front may be let down. It is then found that the map consists of ten cards, each of one color, all the cards being cut away so that part of each is exposed to view. The uppermost card represents the Quaternary, and all is cut away except so much as correctly represents the Quaternary beds on the surface of the region. The next card below it exhibits the Neocene areas in the same manner, cropping out from underneath, and extending beyond, the Quaternary. Then follows the Eocene, succeeded by the Cretaceous, which again is underlaid by the Jurasso-Triassic, and so forth. Finally, the foundation represents the Archæan systems collectively, and is seen exposed where the well-known Archæan areas occur. The fact of superposition of the formations is brought home to the student by this device, while denudation is illustrated by the cutting away of parts of the several cards. Such resultant phenomena as inliers and outliers are seen, also escarpments, the edge of each card forming one in miniature; while by tilting or bending the cards, dip and strike with synclinal and anticlinal folding may be illustrated as well as conformability of stratification. One important advance which the inventor has made since the earlier output of his work is the embossing of the Archæan foundation and all the superposed strata so as to bring the whole to a plane surface.

More recently Mr. Ives has been occupied with the problem of constructing relief maps combining strength and lightness with moderate cost, printed maps being used to furnish the geographical details in which relief maps are often so deficient. One novel feature is the combination of distinctive colors, to represent successive levels, with actual relief. Regions that are less than one hundred feet above sea level are colored buff; from one hundred to five hundred, light green, and so on; there being eight stages in all, represented by eight well-contrasted colors.

These maps are made of specially prepared paper, and the means by which the inventor contrives to emboss them while still retaining the register—that is to say, making the printing on the map exactly correspond to the mountain peaks and river courses of the embossed foundation—is a secret not yet divulged.

The structural and artistic finish of these maps exhibits the painstaking of one who himself appreciates the value of his work. They received a diploma and medal at the Columbian Exposition, both in the Liberal