SCIENCE-GOSSIP 



75 



What is Heat? A Peep into Nature's Most Hidden 

 Secrets. By Fredk. Hovenden, F.L.S., F.R.M.S. 

 370 pp. demy 8vo., and upwards of 90 illustra- 

 tions. (London : W. B. Whittingham and Co., 

 Limited, 1894.) Price 15s. 



This book is wanting neither in boldness, 

 originality nor courage of opinion on the part 

 of the author. To say that his views upon the 

 study of physical subjects are conventional would 

 be incorrect, and it is a source for speculation 

 whether future investigations will entirely confirm 

 the theories propounded in this work. Two things 

 are, however, very evident, Mr. Hovenden's 

 earnestness and 

 enthusiasm ; to 

 which may be 

 added an honest- 

 ness of purpose 

 in trying to 

 throw new light 

 into an obscure 

 subject. The 

 author is clearly 

 one of those 

 students who 

 do not take 

 anything for 

 granted; and, 

 having to his 

 own satisfaction 

 enunciated a 

 theory, or de- 

 molished a 

 theory of some 

 one else, he 

 places his views 

 before us plainly. 

 The future will 

 decide the 

 vitality of these 

 views. 



In discussing the kinetic theory, he refers to it 

 as follows : " Now the kinetic or dynamical theory 

 also supposes that not only are these particles at a 

 certain average distance apart but they are also in 

 perpetual motion of impact or near impact and 

 recoil, like so many atomic pugilists hitting each 

 other or nearly approaching each other and 

 recoiling in a linear direction, now hitting and 

 approaching at one point then at another," etc. 



Later the author figures the obverse and reverse 

 of an Egyptian coin, over 2,000 years old, now 

 in the British Museum, and says: "The kinetic 

 theorists tell us that the particles (atoms or 

 molecules) of which the coin is built up have been in 

 a state of heterogeneous motion for these 2,000 odd 

 years, a motion where the particles are impacting 

 and recoiling, and after impact ' each molecule has 

 its course changed and starts on a new path ' — 

 that is, the volume of the coin has been ever 

 changing for over 2,000 years ! Reader, use your 

 good sense, can you imagine such a condition 

 possible ? " 



The Birth of a Vortex Ring 

 Fig. 32 in " What is Heat.". 



We should like to quote considerably from this 

 work had we space available, for it is one which 

 will interest many people. We must, however, be 

 content to suggest that our readers obtain the book 

 for themselves, and we trust, when they come to 

 discuss it, they will avoid arguments accompanied 

 by actions like that of the molecules as described 

 by "the kinetic theorists," who are so beloved by 

 the author. The book is full of pretty and easy 

 experiments, which are well illustrated. By the 

 courtesy of the publishers we reproduce fig. 32, 

 showing the birth of a vortex rin^, which is 

 followed by other figures or descriptions of its 

 growth, differentiation, reproduction and death. 



We will leave to our readers the pleasure of 

 mastering Mr. Hovenden's own conclusions, for 

 they would spoil by condensation. Whether they be 

 right or whether they be wrong they are pleasantly 

 told and are well worth examining. J. T. C. 



Short Studies in Nature Knowledge : An introduction 

 to the Science of Physiography. By William Gee. 

 321 pp. 8vo., with 117 illustrations. (London : 

 Macmillan and Co., 1895.) Price 3s. 6d. 



Mr. Gse has 

 told his story 

 brightly and 

 with judgment, 

 and his pic- 

 torial examples 

 are judiciously 

 selected. The 

 work is divided 

 into a dozen 

 chapters, each 

 treating of some 

 great feature of 

 the earth's sur- 

 face. The titles 

 of these chapters 

 explain their 

 contents, being 

 such as " The 

 Great Globe It- 

 self " ; " Moun- 

 tains, Valleys, 

 and Great 

 Plains" ; "Scen- 

 ery and its 

 Causes" ; "Riv- 

 ers and their 

 Work," and so 

 forth. Altogether it is a bright book, well suited 

 to young people, and will make a good school 

 prize. 



Wayside and Woodland Blossoms : A Pocket Guide 

 to British Wild-floii'crs for the Country Rambler. 

 By Edward Step. 179 pp. small 8vo., with 128 

 coloured and 23 plain plates. (London and New 

 York : Frederick Warne and Co., 1S95.) Price 

 7s. 6d. 



Messrs. Warne and Co., will receive the thanks 

 of many people, both old and young, for placing 

 within their reach this pretty little pocket com pan ion. 

 With its aid the country rambler will be able to 

 make out the names of at least the 17S species of 

 plants illustrated, and through them doubtless 

 many more. Mr. Step's letterpress is concise, and. 

 considering the small space at his disposal, he has 

 got into the pages a large amount of information. 

 Some of his translations of the scientific names 

 are liberal enough, such as that of houseleek, 

 Sempcrvivum : "As its scientific name (from semper, 



