560 



THE POPULAR SCIENCE MONTHLY. 



Extra Census Bulletins : Tables showing the 

 Cereal Production of the Uuited States by Coun- 

 ties, 1881, pp. 36; Repoit on the Manufacture of 

 Fire-Anns and Ammunition, by Charles H. 

 Fitch, 1882, pp. 36 ; Tables showing the Cotton 

 Production of the United States by Counties, 

 1881, pp. 5 ; Keport on the Cotton Production of 

 Louisiana, by Eugene W. Hilsard, 1881, pp. 99. 

 Washington : Government Printing-Office. 



Report on Experiments and Investigations to 

 develop a System of Submarine Mines. By 

 Lieutenant-Colonel Henry L. Abbott. Washing- 

 ton: Government Prin ting-Ufflce. 1SS1. Pp. 444. 



Memoirs of the Science Department of the 

 TJniversily of Tokio. No. 6, The Chemistry of 

 Saki-Brewing, by R. W. Atkinson, B. So., pp. 73 ; 

 No. 7, Report on the Meteorology of Tokio for 

 the Year 1880, pp. 77, with Plates ; and, The 

 Wave-Lengths of some of the Principal Fraunho- 

 fer Lines of the Solar Spectrum, by T. C. Men- 

 denhall. Ph. D., pp. 27. Published by the univer- 

 sity. Tokio, 1881. 



Psychology of the Salem Witchcraft of 1692- 

 By George M. Beard, M. D. New York : G. P. 

 Putnam's Sons. ISS'S. Pp. 112. $1. 



The Science of Ethics. Bv Leslie Stephen. 

 New York: G. P. Putnam's Sons. 1882. Pp. 

 462. $4. 



Antinous. A Romance of Ancient Rome. By 

 George Taylor. From the German by Mary J. 

 Safford. New York: William S. Gottsberger. 

 18S2. Pp. 343. 75 cents. 



Kant's Critique of Pure Reason. A Critical 

 Exposition. By George S. Morris, Ph. D. Chi- 

 cago : S. C. Griggs & Co. 1882. Pp.272. $1.25. 



Science Ladders. Edited by N. d'Anvers. 

 No. 1. Forms of Land and Water, illustrated, pp. 

 67; No. 3, Vegetable Life, illustrated, pp. 78. 

 New York : G. P. Putnam s Sons. 1882. 50 cents 

 each. 



Our Merchant Marine. By David A. Wells. 

 New York: G. P. Putnam's Sons. Pp. 219. 

 $1.25. 



The Gospel of T aw. Bv S. J Stewart. Bos- 

 ton : George H. Eilis. 1882. Pp. 326. $1 25. 



A Geographical Reader. Compiled by James 

 Johonnot. New York : D. Appletou & Co. 

 1SS2. $1.25. 



Geological Sketches at Home and Abroad. 

 By Archibald Geikie, LL. D , etc. With Illus- 

 trations. New York : Mitcmillan & Co. 1882. 

 $1.75. 



Physiognomy. A Practical and Scientific 

 Treatise. "By Mary Olmsfead Stanton. Printed 

 for the Author. San Francisco. 1831. Pp. 851. 



What is Bright's Disease? Its Curability. 

 Philadelphia: Published by the Author. 1882. 

 Illustrated. Pp. 152. $1. 



A Practical Treatise on Diseases of the Skin. 

 By Louis A. Dnhring. M. D. Third edition, re- 

 vised and enlarged. Philadelphia : J. B. Lippin- 

 cott & Co. 1.82. Pp. 685. $6. 



POPULAR MISCELLANY. 



The Great Telescope at Princeton. The 



new telescope for the Ilalsted Observatory 

 at Princeton has been mounted within the 

 past few weeks, and is now ready for work. 

 In magnitude it ranks at present as fourth 

 among the great refracting telescopes of the 

 world, and second in the United States. Its 

 only superiors in size are the Vienna re- 

 fractor, of twenty-seven inches diameter, 



the telescope of the Naval Observatory at 

 Washington, twenty-six inches in diame- 

 ter, and the telescope of Mr. Newhall, at 

 Newcastle, in England, which has an aper- 

 ture of twenty-five inches. A number of 

 still larger instruments are indeed under 

 construction, but it will be some time before 

 any of them are actually in place. The 

 object-glass of the Princeton telescope is 

 twenty-three inches in diameter, and has a 

 focal length of thirty feet. The glass disks 

 were cast by Feil, in Paris, but the telescope 

 was made by Alvan Clark & Sons, of Cam- 

 bridge. Though the telescope is a little 

 smaller than the Washington equatorial, its 

 mounting is considerably heavier and firmer, 

 and is improved in many respects. The 

 regulator of the driving-clock is unusually- 

 powerful, and, to prevent friction and wear 

 of its pivots, its shaft is floated in mercury. 

 The clamps and slow-motions are all man- 

 aged without removing the eye from the 

 eye-piece, and the declination circle is also 

 read from the eye-end by a new and ingen- 

 ious arrangement of the makers. The ob- 

 ject-glass is peculiar in having its two lenses 

 separated by a space of about seven inches, 

 so as to allow a free circulation of air be- 

 tween them, thus greatly diminishing the 

 disturbing effect of changes of temperature. 

 This construction secures also freedom from 

 the " ghosts " (formed by reflection between 

 the lenses) which are so troublesome in 

 many large instruments. The curves of the 

 lenses are not those usually employed, but 

 i are somewhat like those of the Gaussian 

 system, though not so deep. The color and 

 spherical aberration are very perfectly cor- 

 rected, and the performance of the glass, so 

 far as can be judged from a few nights' 

 work, is extremely fine. The instrument is, 

 of course, provided with all the usual mi- 

 crometers, eye-pieces, and other accessories, 

 but as its chief occupation, for the present 

 at least, is to be in the line of stellar spec- 

 troscopy, special attention has been given 

 to the spectroscope, which is the most pow- 

 erful ever made for star-work. It is a direct- 

 vision instrument, on the plan of that used 

 for some years back at Greenwich, though 

 much larger. It was constructed by Ililger, 

 of London, under the kind supervision of 

 Mr. Christie (the present Astronomer Royal), 

 in accordance with his own designs. It has 



