December 26, 1907J 



NA rURE 



175 



nlTiXL'd, but oxidised in place of being- left bright. 

 Recently a new mark has been introduced in Ireland, 

 consisting of a small numbered tag attached to the 

 base of the dorsal fin by means of a ring ; marks of 

 this pattern are made of various size to suit any fish 

 from a smolt upwards. 



ENTOMOLOGY FOR THE YOUNG. 

 ^pHIS book is not a scientific treatise; it is intended, 

 *■ as the author tells us in the preface, " to en- 

 courage the intelligent life-study of insects by our 

 younger folk, to discourage collecting, and to stimulate 

 the profitable employment of one's eyes and ears in 

 town or country." This object is a very estimable 

 one, and the author has done much to produce a 

 book admirably adapted for this purpose. 



It is divided into seven chapters, each containing 

 manv stories of insect life. The general introduction 



deals with all manner of subjects in a clear and very 

 simple way, such as structure, eggs, metamorphosis, 

 fertilisation of plants, the story of the wild arum, re- 

 semblance of plants to insects, &c. Then follows a 

 chapter on beetles, some of our common forms being 

 simply described. Earwigs, cockroaches, crickets, 

 and grasshoppers form the theme of chapter iii., and 

 dragon-flies, May-flies, &c., that of chapter iv. Now 

 .ind again the author, unfortunately, pounces on 

 scientific names. For many reasons, in a book for 

 young people, these are best left out, particularly if 

 wrong ones are used, as on p. 104, where the steel- 

 blue wood wasp (Sirex juvencus) is called Sirex 

 noctilo ! 



Some of the stories form delightful reading, such 

 a-^ the story of the hive bee, p. 207. 



Seventy-six pages are devoted to butterflies and 



1 "The .Story of In-ect Life." By W. P. Westell. Pp. 3)9 ; illustrated. 

 (London : Robert Culley, n.d.) Price 5^. net. 



NO I9QT, VOL. 77] 



moths, and then the final chapter gives a few brief 

 notes on bugs, frog-hoppers, gnats, and other flies 

 that may attract the young person's attention. 



The illustrations from photographs are mostly ex- 

 cellent, and some beautiful pictures are reproduced of 

 localities where water insects abound. The author, 

 unfortunately, in one has made a grievous error, for 

 in Fig. 119 he gives the head of a male mosquito, 

 Tlieobaldia anmdata, as that of a female gnat, and 

 refers to this in the text. For the young we should 

 be just as careful to be accurate as for people more 

 matured. 



The eggs of the vapourer moth are not in a natural 

 position in Fig. 17, and, again, a badly set and 

 damaged tortoiseshell butterfly is clumsily stuck on 

 an iris blossom (Fig. 86) in a very unnatural way. 

 There are also many entomological errors. 



The plates will be sure to attract the young mind, 

 and they are excellently reproduced, but the artist 

 appears to have a quaint idea of some of the insects, 

 such as the blow-fly on plate viii., and also the water 

 boatman. In spite of such faults, the book is one 

 that may be recommended to all young folk, as it not 

 only supplies a want, but fills that want in a clear and 

 pleasant style. Fred. V. Theobald. 



LORD KELVIN. 

 T N N.WURE for September 7, 1876, there was pub- 

 ■'■ lished, with the engraved portrait by Jeans, in 

 the series of " Scientific Worthies," an account of 

 Lord Kelvin, then Sir William Thomson, and of the 

 scientific work, extending then over more than thirtv 

 years, by which he had rendered himself illustrious in 

 physical science. Thirty-one years have elapsed since 

 that appreciation was written, and now we have to 

 mourn that this life of wonderful activity has come to 

 its natural close. .\t the ripe age of eighty-three, as 

 full of honours as of years. Lord Kelvin has passed 

 away. To say that his eye was not dimmed, nor his 

 natural force abated, would be scarcely strictly true, 

 yet he retained to the last the exercise of his intellec- 

 tual powers. The vigour and keenness with which he 

 entered into the discussions at the British Association 

 meeting at Leicester in August last were truly re- 

 markable at his advanced age. It was in the course 

 of making experiments in a corridor in his 'country 

 house, Netherhall, Largs, that he contracted the chill 

 which brought about the fatal end. 



The article of 1876 gave in some detail those scien- 

 tific achievements which had then made him famous; 

 and a glance at its contents will show in brief what 

 these were. While still an undergraduate at Cam- 

 bridge, he had made valuable mathematical investi- 

 gations in relation to Fourier's theorems, and in their 

 applications to the motion of heat and to hydrody- 

 namics. In these investigations will be discovered the 

 foundation of the method of evaluating geological dates 

 from underground temperatures upon which subse- 

 quently he built his famous conclusions as to the age 

 of the earth. In the years which followed, during his 

 early occupancy of the chair of natural philosophy 

 at Glasgow, Lord Kelvin was largely occupied, in 

 constant association with Joule, with the development 

 of thermodynamics, to which not his least contribu- 

 tion was the theory of the dissipation of energy. This 

 was followed by investigations into electrostatics and 

 the theory of magnetism, contact electricity, thermo- 

 electricity, the mechanical energies of the solar system, 

 the calculation of the tides, the size of atoms, and 

 vortex motion. That which, however, directed popular 

 attention to his scientific attainments was not so much 

 these deep investigations as his connection with the 

 more practical problems of ocean telegraphy. The pos- 



