Produced by Verity White, Juliet Sutherland and the Online Distributed Proofreading Team at http://www.pgdp.net [Illustration] SCIENTIFIC AMERICAN (Entered at the Post Office of New York, N. Y., as Second Class Matter) A WEEKLY JOURNAL OF PRACTICAL INFORMATION, ART, SCIENCE, MECHANICS, CHEMISTRY, AND MANUFACTURES. NEW YORK, DECEMBER 18, 1880. Vol. XLIII., No. 25. [New Series.] $3.20 per Annum. [POSTAGE PREPAID.] * * * * * CONTENTS. (Illustrated articles are marked with an asterisk.) Air engine, new 385 Amateur mechanics* 390 American Institute of Architects 389 Architects, American Institute 389 Arctic winter, characteristics of 393 Aquarium (29) 395 Balance attach. for valves* 386 Band saw, hand power* 387 Barometer, chemical (15) 394 Battery, Leclanche, to renew (13) 394 Beetle, Hercules, the* 391 Belts, capacity of (12) 394 Business colleges* 383, 388 Carbons, to solder (20) 395 Chinese women's feet* 393 Chisels, tempering 389 Colleges, business* 383, 388 Engine, air, new 385 Engine, steam, single-acting* 390 Eruption of Mauna Loa 385 Exhibition of bathing appliances 393 Feet, Chinese women's* 393 Fires--causes and prevention 384 Glass spinning and weaving 385 Gun, submarine, new 387 Harbor at Montreal, the 387 Hercules beetle, the* 391 Horse-power of turbines (12) 394 Ice at high temperatures 393 Ice, removing from railroads* 387 Induction coil for transmitter (14) 394 Induction coil, small (26) 395 Invention, schools of 393 Inventions, miscellaneous 390 Inventions, recent 387 Knots, learning to tie 392 Leaves, variegation of 392 Light, what is? 384 London underground railway 389 Mantis, the embrace of the 391 Mechanics, amateur* 390 Montreal, the harbor at 387 Noise, to deaden (9) 394 Nut, safety, improved* 386 Packard's Business College* 383, 388 Patents, decisions relating to 393