700 



THE POPULAR SCIENCE MONTHLY. 



sable water-supplies for large towns are se- 

 cured by their aid. Engineers, however, 

 also provide for the drainage of large towns 

 and districts, the mitigation of inundations 

 on low-lying lands, the reclamation of lands 

 from the sea, and the irrigation of large 

 tracts of land in warm countries by which 

 crops are preserved and famine averted, and 

 they carry out the works for the illumina- 

 tion of streets and houses with gas and 

 electricity. To their credit also are im- 

 provements in marine engines and increased 

 speed of ocean steamers, and improvements 

 in telegraphy and the laying of submarine 

 cables, and if engineers in the future con- 

 tinue as in the last half-century, increasing 

 and extending the benefits resulting from 

 their works, they will justly be regarded as 

 ranking among the greatest benefactors of 

 mankind." 



The Oyster: A Popular Summary of a 

 Scientific Study, By William K. 

 Brooks. Baltimore : the Johns Hop- 

 kins Press. Pp. 230, with Plates. Price, 

 |1. 



Prof. Brooks is our most thorough and 

 successful student of the oyster. He has 

 devoted a large part of his time to the 

 study for more than ten years past, and, 

 as President Gilman says in the introduc- 

 tion to this book, "he can hold his own 

 not only among naturalists, but also among 

 practical men. He has dredged in every 

 part of the [Chesapeake] bay. To use his 

 own words, he has tonged oysters in five dif- 

 ferent States; in the warm waters of the 

 South he has spent months under the broil- 

 ing sun, wading over the sharp shells which 

 cut his feet like knives, studying the oysters 

 'at home.' He has planted them, he has 

 reared them by collecting the floating spat, 

 and he has hatched from artificially fertil- 

 ized eggs more oysters than there are inhab- 

 itants of the United States." He has also 

 studied the experience of other States and 

 countries, and has gathered up the knowl- 

 edge of the world in respect to the life of 

 the oyster, " its enemies and its needs, its 

 dangers and its protections." The results 

 of this practical work and these studies are 

 embodied in the present book in familiar 

 style and language for the information of 

 the public. The whole work studies and 



book has been prompted by the fact, which 

 is printed in capital letters, that " the de- 

 mand for Chesapeake oysters has outgrown 

 the natural supply." Prof. Brooks's effort 

 has been to find a way to increase and sup- 

 plement that supply. For this, his essay 

 offers many suggestions of value. 



Popular Lectures and Addresses. By Sir 

 William Thomson. Vol. III. Naviga- 

 tional Affairs. London and New York : 

 Macmillan & Co. Pp. 603. Price, $2. 



Volume third of this serie3 of addresses 

 precedes volume second in publication be- 

 cause considerable matter had been pre- 

 pared on navigational subjects which were 

 assigned to the third volume in the plan of 

 the Beries, before any progress had been 

 made with the geological lectures. The lect- 

 ures included in this volume are one on Nav- 

 igation, delivered to the Science Lecture 

 Association ; a British Association evening 

 lecture on The Tides, with parts of a lecture 

 before the Glasgow Association on the same 

 subject ; a British Association paper on the 

 Influence of the Straits of Dover on the 

 Tides of the British Channel and the North 

 Sea, with appendixes on the tides of the 

 southern hemisphere and the Mediterranean, 

 and a sketch of a proposed plan of pro- 

 cedure in tidal observation and analysis, and 

 on the equilibrium theory of the tides ; and 

 papers on Terrestrial Magnetism and the 

 Mariner's Compass ; Deep-sea Sounding by 

 Pianoforte Wire ; Lighthouse Characteris- 

 tics ; the forces concerned in the laying and 

 lifting of deep-sea cables ; and Ship Waves. 

 To these is appended a concluding paper by 

 Captain Creak, R. N., on the disturbance of 

 ships' compasses by the proximity of mag- 

 netic rocks at considerable depth under wa. 

 ter. 



Natural Selection and Tropical Nature. 

 By Alfred Russel Wallace. New edi- 

 tion, with Corrections and Additions. 

 London and New York : Macmillan & Co. 

 Pp. 492. Price, $1.75. 



Many persons who have been interested 

 by Mr. Wallace's Darwinism, and are not 

 acquainted with his early works, will doubt- 

 less welcome this reprint of two volumes of 

 his biological essays. These papers are popu- 

 lar enough to interest the general reader, 

 while containing able discussions of impor- 



