802 Chronicles of Science. [-^pi'ilj 



are extremely jDretty as representations of osculating ciirves, but 

 we want more positive facts in support of tliem before tbey can 

 be accepted as final explanations. 



In Buok II. we have the investigation of ocean currents, wliich 

 are all attributed to the action of vis inertioe, but here the author's 

 hobby runs away with him a Httle, for at page 105 he says : — 



" Why, if the trade- winds result from the heating action of the 

 sun, they should continue to blow at night just as in the daytime, 

 is, it appears to me, not easy to understand." 



The action of a heated surface in causing an ascending current 

 of air does not cease at nightfall over large areas like Central Asia, 

 as it does in the case of small islands, where the diurnal alternation 

 of land and sea breezes holds good. An extensive circulation of 

 air, once set going, is not easily diverted into other channels. 

 However, the monsoons and coast winds in general offer a serious 

 objection to Mr. Jordan's views, and are in favour of the interpre- 

 tation generally received. 



Book III. treats of vis inertise and gravitation ; and here at the 

 outset we are met by a new principle — evanescence. "In this 

 term comprehending the unknown laws which control matter 

 throughout its existence, and by it inferring that matter has not 

 always existed, and that in course of time it will cease to exist ; 

 presuming, of course, that it is only reasonable to suppose that 

 something immaterial existed from wliich it had its origin, and 

 that when it has run its course and ceased to exist something im- 

 material evolved from it will exist after it." 



Not havmg seen the author's other work, ' The Elements,' we 

 are at present unable to understand how he proposes to create 

 matter. 



The chapter on tides is happier, and the explanation of the 

 retardation of spring and neap tides respectively for a day or two 

 after the moon's changes have taken place is clear and intelligible. 



There is one very serious objection to the book as a whole — the 

 style is confused to the last degree, and it is often necessary to read 

 a page two or three times to make sure tliat you have caught the 

 author's meaning. When he is stating two alternatives, each is 

 given at full length, so that the occasional use of the words, " and 

 vice versa" would have reduced the size of the book by at least 

 twenty pages, and made it much more intelligible. 



In the last Chronicle we referred briefly to the synoptic charts 

 of the Indian Ocean, submitted to the British Association by Mr. 

 Meldrum, Secretary of the Meteorological Society of the ^lauritius. 

 These charts present some features of great interest when compared 

 with those issued by Le Verrier for Ihe North Atlantic. Mr. 

 Meldrum's long experience of the weather of those seas renders 

 whatever he may say about it well worthy of attention. However, 



