390 



NATURE 



[September 15, 1923 



winning' it on a very large scale. It describes also the 

 investigations on the winning and the utilisation of 

 peat undertaken by the Fuel Research Board during the 

 past four or five years. These investigations were the 

 preparation of air-dried machine peat in an Irish bog, 

 but by well-known Continental methods and on a very 

 small scale, together with the establishment of the facts, 

 long known abroad, that machine peat dries more 

 uniformly than slane-cut peat, and has a higher value 

 than slane-cut peat of the same calorific power. 



The report is disappointing inasmuch as it shows 

 that the Fuel Research Board has not made any serious 

 attempt to grapple with the problems of the winning 

 and the utilisation of peat. On the other hand, it is 

 valuable since it shows that several attempts to solve 

 these problems are being made in Germany, Sweden, 

 Russia, and Canada. Prof. Purcell's detailed and critical 

 descriptions of the peat industries of northern Germany, 

 Sweden, and Canada are interesting and instructive. 

 One would have expected, however, that the Fuel 

 Research Board's contribution to the solution of these 

 problems during the past four or five years would have 

 been considerably more than a full description of what 

 other and poorer countries are doing in regard to these 

 important matters. Hugh Ryan. 



El Arte de los Metales (Metallurgy). Translated from 

 the Spanish of Alvaro Alonzo Barba, by Ross E. 

 Douglass and E. P. Mathewson. Pp' ix -1-288. 

 (New York : J. Wiley and Sons, Inc. ; London : 

 Chapman and Hall, Ltd., 1923.) lys. 6d. net. 



The earliest known work on American metallurgy was 

 written by Alvaro Alonzo Barba, a priest of Potosi in 

 Bolivia, and was published in Spain in 1640 and 

 several times reprinted. This book, of great historical 

 interest, has now been fully translated by two American 

 metallurgists, and forms an important technological 

 document. The most valuable feature of the work 

 is its detailed description of the methods of extracting 

 silver from its ores practised in Bolivia, a region in 

 which metallurgical skill had at that time attained to 

 a very high level. Amalgamation and the processes 

 connected with it are here described minutely, and in 

 a straightforward fashion, with simple diagrams. 

 Barba was not a profound thinker, and accepted the 

 current superstitions regarding ores and minerals 

 without question, comparing in this respect very 

 unfavourably with his great predecessor Agricola ; but 

 his shrewdness in practical matters and his close 

 acquaintance with the work of smelting and extraction 

 on a large scale are evident throughout. The transla- 

 tion, except for a few explanations of technical terms, 

 inserted in brackets, is not annotated, so that the 

 student will do well to read it in conjunction with 

 Hoover's remarkable translation of Agricola, with its 

 abundant historical notes. C. H. D. 



An Introduction to Stratigraphy (British Isles). By 

 Dr. L. D. Stamp. Pp. xv 4-368. (London: T. 

 Murby and Co., 1923.) 105. net. 



This is a distinctly original work that will be of service 

 to very many students who are unable to follow current 

 literature as it appears. Dr. Stamp brings together, 



NO. 281 I, VOL. 112] 



with good references, results recently obtained b> 

 others, but adds to them by his personal know!fd'_" 

 and his methods of appreciation. Sections sho. 

 the mode of deposition of various series, and skt-i< ii 

 maps of their distribution, give unusual interest to what 

 might have been a mere description of the part played b\ 

 each formation in the structure of the British Isles. A 

 examples, we may take the general map and the small 

 local section (pp. 146 and 147) dealing with the Mill- 

 stone Grit, and the suggestive map (p. 170) of Brit. in 

 in the Permian period, with its stream-notched uplamis 

 supplying material to the basins in the midlands and 

 the south. Not content, the author gives us an 

 enlarged detail of the Comubian area on p. 175. 

 Dr. Stamp (p. 241) is not so bold as Mr. E. Greenly in 

 carr\'ing his Cretaceous strata across the peneplane of 

 Snowdonia. He writes throughout, in spite of very 

 concise limits, as if he were actually viewing from an 

 aeroplane the geographic features of the (Mst. 



G. A. J. C. 



Primitive Tider i Norge : En aversigt over stenalderen. 

 Av Haakon Shetelig. Pp. iv -t- 380. (Bergen : John 

 Griegs Forlag, 1922.) n.p. 



Dr. Shetelig, in his introduction, points out that in 

 few countries in Europe does written histor\' begin at 

 so late a date as in Norway. This gives to the stud> 

 of prehistoric antiquities in that country a position 01 

 peculiar importance. For archaeologists generally the 

 prehistory of the area of which Norway forms a part 

 is also of particular interest, especially in its earlier 

 stages, in view of its relation to that of the rest of 

 Europe ; it is there that we find the evidence for the 

 earliest stages of neolithic culture. On both accounts, 

 therefore, Dr. Shetelig's study of the Stone Age in 

 Norway is welcome. For students outside his own 

 country its value will lie largely in the author's survey 

 of the latest views of Norwegian men of science on 

 Scandinavian archaeology and the relations of Norwa\ 

 in the Stone Age to the rest of this area. F>om thi- 

 point of view his chapters on the first appearance of 

 man in Norway, the transition to the New Stone Age, 

 and the kitchen-middens are particularly worthy of 

 note, as also is his account of Stone Age art, the trade 

 in amber, and the use of jade.. The book is fully and 

 admirably illustrated. 



How to Paint Permanent Pictures. By Prof. M. Toch. 

 Pp. 105. (London : Scott, Greenwood and Son ; 

 New York : D. Van Nostrand and Co., 1922.) 75. 6d. 

 net. 



The reviewer has often wondered, when looking at 

 paintings of great merit which are gradually fading 

 away or cracking in pieces, why artists do not spend a 

 Httle time in learning something about their materials. 

 In many cases they are probably at the mercy of the 

 dealers. It would seem desirable, therefore, to direct 

 attention to this small book by Dr. Toch, which deals 

 with the properties of pigments simply yet scientifically, 

 and should be valuable to all who paint pictures. In 

 it are described those colours which are permanent 

 and those which may be expected to fade away more 

 or less completely with lapse of time. Varnishes are 

 also discussed. 



