!20 



NATURE 



[July 5, 1894 



and to know something about, without pledging himself 

 to the accuracy of the conclusions which the experts 

 draw. In this book he will find the definitions and the 

 grammar of the subject lucidly explained, and if he be 

 at all familiar with the use of planetary tables and 

 understand that much ridiculed but nevertheless valuable 

 science " the use of the globes," he will be able to 

 construct, or rather to erect, a horoscope with 

 certainty, and perhaps edification. Naturally, I have 

 experimented in my own case, but I cannot say that the 

 result has thrown a great deal of light, either on my 

 character, my circumstances, or my future condition, on 

 all points of which I expected information. But I have 

 learnt one caution, that it is not desirable to operate on 

 anyone, in whom we may be interested, indiscriminately, 

 because the result may not be flattering, but is apt to be 

 even disagreeable. A cynic might suggest that since 

 there are more failures than successes in the world, it is 

 necessary to connect a preponderance of gloom and dis- 

 appointment with planetary configuration. It seems 

 especially that Uranus is responsible for much that 

 could easily be dispensed with, and one cannot help con- 

 gratulating those who lived before his presence and 

 influence were discovered. But if this is our flippant 

 view, the authors, on the other hand, regret that the older 

 astrologers were without the guidance that a knowledge 

 of the motions of Uranus and Neptune could have 

 afforded, and recognise the possible existence of yet 

 unknown planets, that not only shape our destinies but 

 also disturb the accuracy of astrological prediction. 

 There is, however, no hint that the theoretical determina- 

 tion of horoscopes compared with the observed facts of 

 individual life will in time lead to the assignment of the 

 position of a hypothetical planet, as the perturbations of 

 Uranus revealed Neptune. 



Not a small portion of the book is taken up with the 

 description of the horoscopes of distinguished men. 

 How far they support the contention of the authors, and 

 can be quoted as successes in astrological inquiry, must 

 be left to a closer student of them and of history than I 

 can claim to be. Mr. Gladstone, it seems, was so in- 

 discreet as to admit that he was born about breakfast 

 time. That might seem a sufficiently vague indication \ 

 in these days, but, nevertheless, his horoscope appears in 

 this gallery ; but whether his admirers or his opponents 

 will best agree with the estimate of character drawn, is a 

 matter of doubt. We are sure only a few will see that 

 the fact that the tail of Capricorn, said to bring danger 

 from beasts, conjoined with Mars, affords an explana- 

 tion of the "historic attack upon Mr. Gladstone by a 

 cow." The incident of the ginger-bread-nut is apparently 

 still unexplained. 



The book concludes with a reprint from the Universily 

 Ma)^ii:ine of 1880, of Mr. Trent's paper on " The Soul 

 and the Stars." We are told in the inlroduclion that the 

 original grew out of a controversy on the topic of reincar- 

 nation, forsooth, and further that it is commended to the 

 reader's indulgence as an honest attenipt to elucidate a 

 subject which ninety-nine out of a hundred understand 

 just sufficiently to misunderstand. Having no claims to 

 t>e the hundredth man, we must leave this honest attempt 

 with a simple reference for the benefit of those who are 

 interested in ihc subject. W. E. I'. 



NO. 1288, VOL. 50] 



NAVAL ENGINEERING. 



Elementary Lessons in Steam Machinery and the Marine 

 Steam Engine. By Staff-Engineer J. Langmaid, R.N., 

 and Engineer H. Gaisford, R.N. (London: Mac- 

 millan and Co., 1S93.) 



THIS work consists of a series of elementary lessons 

 in steam machinery, and a short description of the 

 construction of a battle-ship, intended for the use of junior 

 students, and especially for the naval cadets in H.M.S. 

 Britannia. The syllabus of subjects is based on the plan 

 adopted by the Science and Art Department. 



The first lesson relates to exact measurements, by the 

 use of standard rules and gauges ; the meaning of strain, 

 stress and strength, factor of safety, &c. ; the second and 

 third upon themetals used in machinery and shipconstruc- 

 tion ; the fourth and fifth upon rivets and rivetted joints, 

 and various kinds of screws ; the sixth, seventh, and eighth 

 upon shafting, shaft-bearings, and toothed gearing ; the 

 ninth upon friction ; the tenth, eleventh, and twelfth upon 

 stuffing-bo.xes, packing, pipe-joints, valves, cocks, and 

 pumps ; the thirteenth to the eighteenth upon boilers and 

 boiler mountings ; and the nineteenth to the twenty- 

 fourth upon the principal component parts of the marine 

 engine, the indicator and indicator diagrams, and screw 

 propellers. The last one contains a short description 

 of the construction of a battle-ship. 



These lessons appear well adapted for imparting to 

 junior students a simple course of instruction, as a 

 preliminary to a thorough study of marine engineering, 

 which is the object the authors had in view. They are 

 illustrated by well-executed and instructive sectional 

 drawings of boilers and marine engines, and with sketches 

 of many of the principal details of boiler and engine 

 work. These include a very useful sketch, for a young 

 student, of a section of cylinder, with movable piston and 

 slide valve. There are also two very clear views of the 

 triple-expansion engines fitted to H.M.S. Sappho and 

 Scylla, which are representative of a large number of 

 engines in the Navy, these ships being two out of a class 

 of twenty-nine that have been recently built under the 

 Naval Defence Act of 1889. 



The terms strain and stress might be dealt with more 

 accurately than is done on pages 8 and 9. Strain is de- 

 fined as change of form due to load, and stress as the 

 force or forces producing the strain. Tensile strain is 

 then described as " a stress that tends to stretch the body 

 acted upon " ; and we find the various kinds of stress 

 described as follows : Tensile strain, compressive stress, 

 torsional or twisting /ora; bending /orce, and shearing 

 force. The want of exactness in the use of these terms 

 might easily be corrected. We observe that the thick- 

 nesses of the shell-plates of large marine boilers are 

 stated to be i in. to 1] ins. In the largest marine boilers, 

 however, the shell-plating exceeds lA ins. 



The description of the construction of a battle-ship is 

 very brief and general, but 11 serves at least to call atten- 

 tion to a very useful " Text book of Naval Architecture " 

 by Mr. J. J. Welch, formerly instructor at the Royal 

 Naval College. In speaking of the division of a battle- 

 ship into water-light compartments, it is stated that " the 

 total number of water-tight compartments is considerably 

 over one hundred ; several of them might fill without 



