1 8 SCIENTIFIC CA TALOGUE. 



Tanner. FIRST PRINCIPLES OF AGRICULTURE. By 

 HENRY TANNER, F.C.S., Professor of Agricultural Science, 

 University College, Aberystwith, Examiner in the Principles of 

 Agriculture under the Government Department of Science. i8mo. 

 is. 



Taylor. SOUND AND MUSIC : A Non-Mathematical Trea- 

 tise on the Physical Constitution of Musical Sounds and Harmony 

 including the Chief Acoustical Discoveries of Professor Helm 

 holtz. By SEDLEY TAYLOR, M.A., late Fellow of Trinity Col 

 ledge, Cambridge. Large crown 8vo. Ss. 6d. 

 " In no previous scientific treatise do we remember so exhaustive and 



so richly illustrated a description of forms of vibration and of 



wave-motion in fluids" Musical Standard. 



Thomson. Works by SIR WYVILLE THOMSON, K.C.B., F.R.S. 

 THE DEPTHS OF THE SEA: An Account of the General 

 Results of the Dredging Cruises of H.M. SS. "Porcupine" and 

 "Lightning" during the Summers of 1868-69 and 70, under the 

 scientific direction of Dr. Carpenter, F.R.S., J. Gwyn Jeffreys, 

 F.R.S., and Sir Wyville Thomson, F.R.S. With nearly 100 

 Illustrations and 8 coloured Maps and Plans. Sdcond Edition. 

 Royal 8vo. cloth, gilt. T>\S. 6d. 



The Athenaeum says : " The book is full of interesting matter, and 

 is written by a master of the art of popular exposition. It is 

 excellently illustrated, both coloured maps and woodcuts possessing 

 high merit. Those who have already become interested in dredging 

 operations will of course make a point of reading this work ; those 

 who wish to be pleasantly introduced to the subject, and rightly 

 to appreciate the nexvs which arrives from time to time from the 

 ' Challenger, "* should not fail to seek instruction from it." 



THE VOYAGE OF THE " CHALLENGER." THE ATLAN- 

 TIC. A Preliminary account of the Exploring Voyages of H.M. S. 

 "Challenger," during the year 1873 and the early part of 1876. 

 With numerous Illustrations, Coloured Maps & Charts, & Portrait 

 of the Author, engraved by C. H. JEENS. 2 Vols. Medium 8vo. 42^. 

 The Times says : " It is right that the public should have some 

 authoritative account of the general results of the expedition, and 

 that as many of the ascertained data as may be accepted with con- 

 fidence should speedily find their place in the general body of 

 scientific knoivledge. No one can be more competent than the 

 accomplished scientific chief of the expedition to satisfy the public in 

 this respect. . . . The paper, printing, and especially the numerous 

 illustrations, are of the highest quality. . . . We have rarely, if 

 ever, seen more beautiful specimens of wood engraving than abound 

 in this work. . . . Sir Wyville Thomson's style is particularly 

 attractive ; he is easy and graceful, but vigorous and exceedingly 



