September i6, 1920] 



NATURE 



81 



ductions from excellent photofjraphs of timber 

 operations and forest scenes in many parts of the 

 British Empire. The inclusion in the work 

 (pp. 328-84) of the tables of strengths of woods, 

 which were published by Laslett, is probably justi- 

 fied by the fact that Laslett 's book is out of print. 

 These tables are of considerable value, but as 

 Laslett had not at his disposal apparatus for 

 determining- the moisture contents of the woods 

 examined, the figures are not so trustworthy as they 

 seem. It would certainly be preferable in future, 

 as Mr. Howard admits, to conduct experiments 

 on woods " with some named and specific per- 

 centage of moisture." Moreover, we are now- 

 aware, thanks to the numerous tests carried out 

 of late years at the Forest Products Laboratory, 

 Madison (U.S.A.), that there is a remarkable 

 variation in the properties of timbers of the same 

 species from different logs and from different 

 localities. That timbers are in no way comparable 

 with metals in the uniformity of their physical 

 characteristics is of course well known. 



.■\ chapter on the artificial seasoning of timber, 

 with a note on laboratory and working tests, con- 

 tributed by Mr. S. Fitzgerald, will prove useful. 



There are errata and misstatements in this 

 book, but they are not of a kind to detract much 

 from its real value, which consists in the 

 thoroughly practical nature of the information 

 given on the uses, conversion, and utilisation of 

 so many kinds of timber. Some of the inaccu- 

 racies may, however, be pointed out. It is, un- 

 fortunately, not true that, as stated on p. 118, 

 "larch disease has practically disappeared." The 

 explanation of the name "sycamore" on p. 266 

 is entirely erroneous, and is an instance of the 

 strange fascination that wrong etymology has 

 for many people. The word "sycamore" was 

 originally applied in Greece to a species of Ficus, 

 and is now transferred in Kngland to the large- 

 leaf maple, Acer pseudoplatanus, and in America 

 to the Western plane, Plaianus occidentalis. A 

 whole page — p. 164 — is devoted to the etymology 

 of the term "wainscot oak," about which there 

 is no doubt. It could have been expressed in three 

 lines. "Wainscot " is derived from a Dutch word 

 (fourteenth century) which means "oak wood 

 with a wavy grain"; in other words, "wainscot 

 oak" is "figured oak." Mr. Howard misquotes 

 Skeat, who ("Concise Etymological Dictionary," 

 P- .S97) expressly warns the reader against the 

 wrong derivation attributed to him by Mr. 

 Howard. A regrettable error occurs on p. 211, 

 whoff Aht'rs prriinnin . thr Kiirnpfan silver fir, is 



called "silver spruce." As is pointed out on 

 pp. 262-63, the latter name can be applied only 



the Sitka spruce [Picca sitchcnsis). Endless 



to 



Fin« example of Afrtcart mAttoganv curl. (From 

 "A MbiiuaI of ihe limbers of ihe World.") 



embarrassment to the landowning class resulted 

 during the war from the confusion between the 



names "silver spruce" and "silver fir." 



The Structure 

 By C. G. 

 H. — Atomic Number {continued.) 

 T I would involve very prolonged work to get the 

 -^ atomic numbers accurately by direct experiment 

 with scattered o-parficles. Fortunately, this is 

 not necessary, as there exist much more con- 



' Continu**] fro-^ p. 54. 



NO. 2655. VOL. 106] 



of the Atom.* 



Darwin. 



venient indirect means of determining them. The 

 invention of a powerful method of studying X-ray 

 spectra enabled Moseley to examine the spectra 

 from a sequence of elements. Whereas visual 

 spectra have a highly complicated structure, and 

 exhibit the same peri«xlicity as do chemical pro- 



