SCIENTIFIC CATALOGUE. 



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. 

 I J. 



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 Svo. %s. 6d. 

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



sy richly illustrated a description of for7ns of vibration and oi 



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. Second Edition. 

 Royal Svo. cloth, gilt. t,is. 6d. 



The AthenEeum 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 luoodcuts possessing 

 high merit. Those who have already become interested in dredging 

 operatiofts 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 news which arrives from time to time from the 

 ' Challenge!;^ 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.byC. H. Jeens. 2 Vols. Medium 8vo. 42^. 

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

 authoritative account of the general results of the expedition, and 

 ^ that as 7nany 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 cotnpetent 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. . . . tVe have rarely, if 

 ever, seen more beautiful specimens of wood engraving than abound 

 in this work. . . . Sir Wyville Thomson^ style is particularly 

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



