Jan. 29, 1885] 



NA TURE 



287 



able instrument, is not referred to ; but the integrator which 

 combines appliances for computing areas, moments, and 

 moments of inertia of plane curves is described. This 

 instrument has lately been introduced into ship-drawing 

 offices, and is highly appreciated for the saving of time 

 and labour which can be effected by its use, and for its 

 comparative freedom from error. Complicated calcula- 

 tions can be made with this ingenious piece of mechanism 

 by less highly-skilled draughtsmen than are required for 

 performing the ordinary arithmetical calculations. This 

 is a very important matter in mercantile shipyards, where 

 the supply of scientifically-trained draughtsmen is not 

 great. In referring to this point Sir E. J. Reed says 

 that " in most private shipbuilding establishments these 

 lads (drawing-office apprentices) are now required to pass 

 an examination similar to that which candidates undergo 

 for apprenticeship in Her Majesty's dockyards." We do not 

 understand that this is so. It may be the case with one 

 or two firms, but the system is a very exceptional one. 

 Sir E. J. Reed gives a mathematical investigation of the 

 properties of the integrator, and explains how to take 

 off the readings for areas, moments, and moments of 

 inertia. We notice an omission in connection with 

 the figures given for the various constants that re- 

 quire to be applied as multipliers to these readings, for 

 the purpose of converting them into actual units of mea- 

 surement. The particular instrument to which the con- 

 stants apply is not fully stated. The constant for 

 areas, given as 15, and that for the area term in the 

 expression for moment of inertia, given as 240, relate to 

 instruments formerly supplied by M. Amsler, which had 

 a different diameter of area wheel from those now made. 

 We believe that the circumference of the area wheel is 

 now 2'5 inches : so that the two constants which depend 

 upon the size of the area wheel would, in that case, be 

 20 and 320, instead of 15 and 240. 



The final chapters of the treatise deal with general 

 questions relating to the rolling of ships at sea, and the 

 effect of wind-pressure upon stability when ships are sail- 

 ing among waves. The method of obtaining by experi- 

 ment the vertical position of a ship's centre of gravity, 

 and the precautions which have to be adopted in order to 

 ensure fairly accurate results, are described. 



The few omissions and defects we have pointed out are 

 but of minor importance, and do not appreciably affect 

 the general value of this very important treatise. It is 

 not only the largest that has ever appeared in this 

 country, but also the most intelligible, instructive, and com- 

 plete exposition of the principles of stability. It forms a 

 most valuable addition to the science of naval architecture, 

 and one that has long been needed. Till now we have 

 been unable to refer persons desirous of studying the 

 various problems connected with the stability of ships to 

 any work in which they would find the subject treated in 

 a clear and comprehensive manner. Sir E. J. Reed has 

 supplied a want that has long existed. We strongly 

 recommend his book to all who are interested in the 

 subject, and particularly to those whose connection with 

 ships requires them to know upon what conditions sta- 

 bility depends, and how it is affected by all the various 

 circumstances of construction and loading which may 

 arise. Such a treatise should be especially welcome to 

 students. 



OUR BOOK SHELF 

 In the Lena Delta ; a Narrative of the Search for Lieut- 

 Commander De Long and his Companions, followed by 

 an Account of the Greely Relief Expedition and a Pro- 

 posed Method of Reaching the North Pole. By G. W. 

 Melville ; Edited by G. Melville Philips. (London : 

 Longmans and Co., 1SS5.) 



The sad story of the Jeannette Expedition has already 

 been very fully told in the two volumes of journals left by 

 Capt. De Long. Still, we do not object to this more 

 detailed narrative of the experiences in the Lena Delta 

 of those who managed to reach it, by the one most quali- 

 fied to speak of them. It was by the strenuous exertions 

 of Engineer Melville that the bodies of Capt. De Long 

 and his companions were discovered, and that the few 

 survivors were rescued. Concerning the physical and 

 biological conditions of the great swamp formed about the 

 mouths of the Lena, Mr. Melville does not tell us much 

 more than we knew already ; but his continual journeys 

 to and from between the delta and such towns as 

 Yakutsk, Tiumen, and others in this part of Siberia neces- 

 sarily furnish us with many details of interest. As a 

 story of remarkable adventures the book is certainly 

 interesting. Mr. Melville's arctic enthusiasm was not in 

 the least damped by the Jeannette misfortunes. Not 

 only does he describe in the present volume his experi- 

 ences as a member of the Greely Relief Expedition, but 

 he means evidently to attempt to reach the Pole, if for no 

 other reason but that it "may prevent other fools from 

 going there.'' Mr. Melville's plan takes for granted that 

 Franz Josef Land reaches to 85 N., which is probable 

 enough ; and he would therefore propose to utilise this as a 

 basis of operations ; aroundthePolehe supposes that a par- 

 tial " vacuum " exists, and that partly as a consequence the 

 ice-cap there is immovable, held in its place by the islands 

 which he believes surround it. As to getting back when 

 the Pole is reached, Mr. Melville believes that this could 

 easily be effected either by Nova Zembla or Spitzbergen. 

 Of course, the retreat would be secured by the establish- 

 ment of carefully-selected depots. " Finally, I propose 

 to prove this theory of reaching the North Pole by going 

 there myself" Every one will wish him God speed ; 

 and there can be no doubt that the best arctic authorities 

 are agreed that the next expedition should seriously try 

 the Franz Josef Land route. 



Stanford's Compendium of Geography and Travel — 

 Europe. By F. W. Rudler, F.G.S., and G. W. 

 Chisholm, B.Sc. Edited by Sir Andrew C. Ramsay, 

 LL.D., F.R.S. With Ethnological Appendix by A. H. 

 Keane, M.A.I. (London: Stanford, 1885.) 

 This many-authored and much-edited volume is the last 

 of the series of Stanford's well-known " Compendium," the 

 first volume of which was issued some six years ago. 

 That first volume dealt with Africa, and was edited, it 

 may be remembered, by Mr. Keith Johnston, who 

 shortly after publication lost his life attempting to explore 

 the continent which he had so well described. There have 

 been subsequent editions of that volume edited by Mr. 

 E. G. Ravenstein. The succeeding volumes were South 

 America, by Mr. H. W. Bates ; Australasia, by Mr. A. R. 

 Wallace ; Asia, by Prof. Keane and Sir Richard Temple ; 

 and North America, by Drs. Hayden and Selwyn. It will 

 thus be seen that Mr. Stanford has been fortunate in his 

 choice of editors for the several volumes. The Com- 

 pendium professes to be based on Hellwald's German 

 work, but it may throughout be regarded as virtually 

 original. The various editors have put so much of their 

 own into their several volumes, and given to the whole 

 an orientation so essentially English, that it would be 

 difficult to tell which is Hellwald and which the "editors." 

 In the present volume the editors and authors (or one 

 of them, for the title-page is awkward) have wisely 



