438 



NA rURE 



\J\Iarch II, 1886 



while Prof. Young's observations on the sun, now fifteen 

 years old, is the latest information we get in the ap- 

 pendixes on any solar matter, English and foreign work 

 being ignored with a magnificent impartiality. In the 

 same manner V'ogel's work on the spectra of stars, the 

 most extensive which has been accomplished by any one 

 single individual up to this time, is also passed over, as is 

 also Birmingham's work on the red stars. 



We give these as instances of the treatment adopted. 

 No doubt, had the initial idea of the book been carried 

 out in its entirety by the insertion of the most important 

 parts of these memoirs, the size of the volume would have 

 been greatly increased, and this perhaps may be one 

 reason for the violently selective treatment adopted ; but 

 it may be urged on the other hand that the value of the 

 book would have been increased much more than its size, 

 and further, that space might easily have been gained for 

 some of the best modern work by the omission of those 

 papers which, as we have said before, are now purely of 

 antiquarian interest. 



There was one feature in the third edition which we also 

 regret very much to see dropped in the present one. This 

 was a bibliography running over twenty pages, in perhaps 

 its most convenient form, namely, a list of authors and a 

 complete reference to their memoirs, arranged under the 

 larger groupings of the subject-matter. 



Trigonometry for Beginners, as far as ilie Solution of 

 Triangles. By the Rev. J. B. Lock, M.A., Senior 

 Fellow of Gonville and Caius College. (London: 

 Macmillan and Co., 1SS6.) 



'T^HIS book covers exactly the same ground as 

 -•■ Pinkerton's, which we noticed in NATURE, vol. 

 xxxi. p. 148. The two have many good points in com- 

 mon, and we should be well satisfied "to'use either of them 

 as a text-book. IMr. Lock's great advantage is precep- 

 torial skill in arrangement and exposition. On this score 

 he deserves much credit indeed. There are very few 

 ])oints on which it is possible to suggest improvement. 

 The retention of the expression "circular measure" in 

 all its former importance, notwithstanding the introduc- 

 tion and constant use of the term " radian," is regrettable 

 but not of much consequence : the mode, however, which 

 he employs for indicating the word "radian," e.g. writing 

 -■ for 7r radians, is most unfortunate, and we should hope 

 altogether unacceptable. It is surprising too to find so 

 skilled a teacher following the multitude in condescend- 

 ing to recognise those unnecessary nuisances, "tabular 

 logarithmic sines," &c. Their existence, Mr. Lock says, 

 is due to a typographic difficulty — a statement we hesitate 

 to give assent to ; but, be their history what it may, they 

 serve no purpose nowadays whatever, except to roughen 

 the learner's path. Writers require to give them a foolish 

 name and a special symbol, to alter the formula? for solu- 

 tion, and to burden the learner with additional cautions, — 

 and all for less than nothing. It seems almost malicious 

 indeed to force on a " beginner" such gratuitous absurdi- 

 ties as "natural sines," "logarithmic sines," and "tabular 

 logarithmic sines," when the entities to be dealt with are 

 simply sines and logaritlims of sines. If Mr. Lock in a 

 succeeding edition could see his way to inaugurate the 

 necessary reform here, many teachers would be grateful 

 to him. 



TIte Apparent Movements of the Planets and the Princi- 

 pal Astronomical Phenomena for the Year 18S6. 

 Illustrated with Charts showing the Paths of the 

 Eleven Principal Planets among the .Stars. By William 

 Peck, F.R.A.S. (Edinburgh : Archibald and Peck, 

 1S86) 



Beginners in astronomy will find this little compilation 

 useful. Just the kind of information is brought together 

 in it which persons interested, though not learned, in 

 celestial phenomena want to be supplied with Technical 



language, too, is as much as possible avoided, while 

 sufficient exactness for the purpose in view is usually pre- 

 served. Not, however, invariably ; the statements re- 

 garding the two solar eclipses visible in 1886 are so loose 

 as to be misleading. Eleven miniature maps, showing 

 the paths through the constellations during the present 

 year of seven primary and four minor planets, are neatly 

 executed, and ought to prove acceptable to casual ob- 

 servers. Exception must be taken to the introductory 

 assertion that Copernicus swept away all the " compli- 

 cated machinery of the heavens." His reform of the 

 Ptolemaic system was by no means so complete as Mr. 

 Peck's expression implies. The retention by the Frauen- 

 burg astronomer of the old hypothesis of equable circular 

 motion necessitated, in fact, the employment still of no 

 less than thirty-four circles, by which to make plain, as 

 he said, " the entire structure of the heavens" — that is, 

 the revolutions of the moon and of the six known planets. 



LETTERS TO THE EDITOR 



\Tlie Editordoes not hold himself responsible/or opinions expressid 

 by his correspondents. Neither can he undertake to return, 

 07' to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communicalions. 



[The Editor urgently requests correspondents to keep their letters 

 as short as possible. The pressure on his space is so great 

 that it is impossible otherwise to insure the appearance even 

 of communications containinginterestiiig and novel facts.'\ 



An Earthquake Invention 



In Nature of July 2 last, p. 213, I was accused by Prof. 

 Piazzi-Smyth and Mr. D. A. Stevenson of having attempted to 

 appropriate an invention of Mr. David Stevenson. The in- 

 ^■enlion referred to was the joint introduced by Mr. Stevenson 

 beneath the lamp-tables in certain lighthouses in this country. 



In my reply (Nature, vol. xxxii. p. 573) I pointed 

 out the fact that the a^eismatic joint had been independ- 

 ently invented by several investigators of earthquake pheno- 

 mena, and so far as I was aware Mr. Mallet had appeared to 

 have the prior claim to this invention. My reason for attri- 

 buting the invention to Mr. Mallet is that when speaking of 

 Japanese lighthouses he says : " I was consulted by Mr. .Steven- 

 son as to ihe general principles to be observed, and these 

 edifices have been constructed so that they are presumedly proof 

 against the most violent shocks likely to visit Japan ; not 

 perhaps upon the best po";sibIe plan, but upon such as is truly 

 based upon the principles I have developed " ( Palmieri's 

 "Vesuvius," p. 43). As the aseismatic joints were portions of 

 the lighthouses especially designed to render them proof against 

 earthquakes, I naturally assumed that Mr. Mallet might be the 

 first inventor of the ball-and-plale joint. 



The only occasion on which I have posed as the author of th e 

 aseismatic joint in question, was when Messrs. .Stevenson and 

 Smyth promoted me to that ywiivZ-enviable position. 



Mad these gentlemen recognised the fact that they were only 

 reading a ///v'c/ ;«/<; about bnll-and-plate joints, intercalated in a 

 collection of notes on other subjects, and had they been well 

 acquainted with the recent literature relating to aseismatic tables, 

 they would cer:ainly have refrained from the objectionable accu- 

 sations made on July 2. 



On more th in one occasion I have referred to Mr. Stevenson's 

 work in Japan. As an example of such a reference, Messrs. 

 Stevenson and Smyth may turn to the Times of May 2O — a dale 

 lohich it will be obse/ved is prior to the date oj' their unwarrantable 

 attack. In that paper there is a long letter on " Buildings and 

 Earthquakes " signed with my name. When speaking of my 

 house on shot, I there say, " This experiment was very similar 

 to one cirried out by Mr. David Stevenson with regard to the 

 lamp-tables in several of tlie lighthouses on the coast of Japan. 

 For several rea'ions, among which were the movements pro- 

 duced by w'nd, I abandoned the balls, and now have my house 

 resting at each of its piers upon a handful of cast-iron shot. 

 These shot, which are about the size of buckshot, have so 

 increased the frictional resistance to rolling, that the house is 

 practically astatic, and the motion in the house is in most earth- 

 quakes only about one-tenth of what it is outside." 



I make especial reference to the Times, first because it is a 



