National Geographic : 1912 Apr
Howell's Systematic Collections of Fine Minerals and Rocks Our Washington School Collections are now in daily usein many homes as well as schools and colleges throughout the country. The study of MINERALOGY will become extremely fasci nating when you have authentic specimens at hand. Members of the U. S . Geological Survey and National Museum have aided in the preparation of these collections, careful attention . having been given in their selection in order that they might, in .. " a general way, cover the field of Mineralogy. Collection No. 1 contains 20 Rocks and 20 Minerals. Collection No. 2 contains 40 Minerals. Collection No. 3 contains 40 Rocks. We will send with each of these collections one extra set of Duplicate Fragments, unlabeled; also a descriptive 63-page text book. The unlabeled specimens are used in comparing with the larger labeled specimens, and it will be readily seen how this comparison serves to impress on the mind and make one familiar with the distinctive characters of each rock and mineral. The texts for these collections have been prepared by Mr. J . S. Diller, Geologist with the United States Geolog ical Survey. Each specimen is labeled and the corre sponding number and name of specimen will be found on the cover of the case. There is also a description in the text book pointing out the distinctive characteristics of each specimen and its principal uses. Each collection selected with great care, cor rectly labeled,and placed in a neat,substantial case, a miniature of which is seen in the illustration, and accompanied with an extra set of Duplicate Frag ments, unlabeled. Price, $2.00. When writing please be sure to mention the number of collection desired. Howell's Relief Maps and Models are the World's Standard. Send for catalogue giving full description. HOWELL'S MICROCOSM, 612 17th Street N. W., WASHINGTON, D. C. 2 THE PANAMA CANAL PANORAMA THIS graphic bird's-eye picture of the Panama Canal, bringing out the features which mark the work las the greatest project of engineering history showing the Giant Gatun Dam and Spillway, the enormous cut at Culebra, the big artificial lake, and the long double locks-immediately conveys a vivid realization of the entire work. A limited edition of the Panorama, 10x 19 inches in five colors, has been produced on heavy art mat board, unfolded, ready for framing, 50 cents, postpaid. (Beautifully framed, $3.00, express collect.) DEPARTMENT H, NATIONAL GEOGRAPHIC SOCIETY 16TH AND M STREETS N. W ., WASHINGTON, D. C. "Geographic readers may depend upon the character of our advertisers."