6 SCIENCE AND PIIILOSOPHF. 



Hours of Exercise in the Alps, By Prof. John Tyndali. With Illnstra- 

 tions. ]_'mo. Clolh, :f2.00. 



Faraday as a Discoverer. A Memoir. By Prof. John Tyndall. 12mo. 



Cloth, $1.00. 



Fragments of Science for Unscientifi.c People. A Series of Detached 

 Kssays, Lectures, and Reviews. IJy Prof, ^ohn Ttndall. Kevised and en- 

 larsed edition. 12mo. Clutli, $2.50." 



Address delivered before the British Association, assembled at 

 Belfast. By Prof. John Ttndall. E<-viscd, with Additions, by the Author, 

 since the Delivery. 12mo. Paper, 50 cents. 



Essays on the Floating; Matter of the Air, in Relation to Pu- 

 trefaction and Infection. By Prof. John Ttndall. With Iliubtrations. 

 12mo. Cloth, $1.50. 



Research «?s on DiamagTietism and Magn^-Crystallic Action. In- 

 cluding the Question of Diamagnetic Polarity. By Prof. Joh.n Ttndall. "With 

 10 Plates. 12mo. Cloth, $1.50. 



Xiouis Pasteur : His Life and Labors. By his Son-in-Law. Translated from 

 the French bv Ladt Claud Hamilton. With an Introduction by Prof. John 

 Ttndall. 12mo. Cloth, $1.25. 



WORKS OF PROFESSOR R. A. PROCTOR. 



The Moon: Her Motions, Aspect. Scenery, and Physical Condition*, with Two 

 Lunar Photofrraphs, and many Illustrations. By E. A. Pkoctok. New edition. 

 12mo. Cloth, $3.50. 



The Expanse of Heaven. A Series of E^sars on the Wonders of the Firma- 

 ment. By R. A. Pkoctoe. 12mo. Cloth, $2.00. 



Lii^ht Science for Leisure Hours. F.'imiliar Essays on Scientific Subjects, 

 Natural Phenomena, etc. By E. A. Proctok. 12rao. Cloth, $1.75. 



Other "Worlds than Ours : The Plurality of Worlds, studied under the Lipht 

 of Recent Scientific Researches. By R. A" Peoctoe. With Illustrations, some 

 colored. 12mo. Cloth, |2.50. 



Our Place amonpr Infinities. A Series of Essays contrastinfr our Little 

 Abode in Space and Time with the Infinities around us. To which are added 

 Essays on the Jewish Sabbath and Astrology. By R. A. Pkoctor. 12mo. 

 Cloth, $1.75. 



ASTRONOMY. 



Elements of Astronomy. By Robert Stowetl Ball. LL. D., F.R. S., 

 Andrews Professor of Astronomy in the ITniversitv of Dublin, Royal Astronomer 

 of Ireland. With Illustrations. " lOmo. Cloth, $2.25. 



Origin of the Stars, and the Causes of their Motion and their 

 Light. By Jacob Ennis. 12mo. Cloth. $2.00. 



Elements of Astronomy ; accompanied with numerous IllnstraHnns. a Colored 

 Representation of the Solar, Stell.ir, and Nebular Spectra, and Arapo's Celestial 

 Cnarts of the Northern and the Southern Hemisuheres. By J. Nor.man Lock- 

 TER, Fellow of the Royal Astronomical Society. Editor of "Nature," etc. Ameri- 

 can edition, revised and specially adapted to the Schools of the United States. 

 12rao. Cloth, $1.50. 



Astronomy with an Opera-Glass. A Popular Introduction to the Study 

 of the Starry Heavens with the Simplest of Optical Instruments. AVith Ma])S 

 and Directions to facilitate the Recognition of the Constellations and the Principal 

 Stars visible to the Naked Eye. By Gakrett P. Skrviss. Svo. Cloth, $1.50. 



Outlines of Astronomy. By Sir J. J. W. Hekschel. With Plates and 

 Woodcuts. Eleventh edition. Svo. Cloth, $4.00. 



