372 



NATURE 



[May 19, 1921 



the extension, from the lower outer angle of each 

 cheek-bone or zygomatic arch, of a large side-process 

 buttressed by a horizontal platform beneath the orbit. 

 Mr. Longman considers that these processes were for 

 the support of large cheek-pouches, as in the pocket 

 gophers of North America. However that may be, 

 such extensions are characteristic of the Nototheres, 

 and an exaggeration of the character, with the cor- 

 related modifications, would scarcely warrant the 

 generic separation of this species from Nototherkim 



Front view of the cranium of Euryzygoma, slightly restored. 

 Actual width 680 mm. 



Mitchelli and JV. tasmanicum. Mr. Longman, how- 

 ever, states that the upper premolar tooth, on which 

 some stress has been laid by classifiers of marsupials, 

 is oval in the normal Nototherium, but subtriangular 

 in Euryzygoma. From the half-tone reproduction of 

 a greatly reduced photograph it is impossible to check 

 the alleged differences. In all other technical respects 

 Mr. Longman's presentation of his results calls for 

 ptaise. He is also to be congratulated on an interest- 

 ing discussion of the most remarkable Diprotodont yet 

 discovered. 



Alaska magnetic tables and magnetic charts for 

 1920 have been published by the U.S. Coast and Geo- 

 <ietic Survey as Special Publication No. 63, prepared 

 by Daniel L. Hazard, Assistant-Chief, Division of 

 Terrestrial Magnetism. Charts are given for the 

 several magnetic elements, declination, inclination or 

 dip, and horizontal force or intensity. The area 

 covered by the discussion includes not only Alaska, 

 hut also its boundary waters, parts of the North 

 Pacific, the Bering Sea, and the Arctic. Declination 

 and dip are given on the charts to each 1° and the 

 liorizontal force for intervals of 001 C.G.S. unit. 

 Results are for observations since 1870, and the data 

 now published are said to be sufficiently numerous to 

 show areas of local disturbance, some of which are 

 remarkable. Lines of equal annual change of declina- 

 tion are shown on the isogonic chart, but they are 

 stated to be only rough approximations to the truth. 

 East declination is decreasing in Alaska except in the 

 south-eastern portion, where the change is negligible. 

 It is not considered advisable at present to attempt 

 to draw lines of equal annual change of dip or of 

 Tiorizontal force. The tabular matter shows that the 

 dip appears to be decreasing in the greater part of 

 Alaska at the rate of i' or 2' a year, and that the 

 annual change of horizontal intensity is decreasing 

 In the southern part of the territory and increasing in 

 the northern, but the rate of change is small. 

 NO. 2690, VOL. 107] 



We have received from Dr. J. Newton Friend a copy 

 of his paper entitled "Iron in Antiquity," reprinted 

 from the Transactions of the Worcestershire Natural- 

 ists' Club. Dr. Friend recalls the statement of Caesar 

 that the Britons were accustomed to use bars of iron in 

 place of coins as currency. Several hundreds of these, 

 which have escaped, more or less, the ravages of 

 time, have been found and placed in different 

 museums, notably the British Museum and the local 

 museum at Worcester. They resemble swords and 

 consist of a flat and slightly tapering blade with blunt 

 vertical edges. Owing to corrosion all the bars have 

 suffered some loss in weight, but many of them have 

 been only slightly oxidised, and a rough estimate of 

 their original weight can be made. The weights are 

 found to approximate 309 grams, or some mul- 

 tiple or sub-multiple of this amount. In all, six 

 different denominations have been found. In spite of 

 their resemblance to swords, Dr. Friend advances good 

 reasons for considering that these are the currency 

 bars referred to by Caesar, the use of which, indeed, 

 dates back to the early Greeks, and survives to-day in 

 some parts of Africa. His paper also deals at some 

 length in an interesting way with early British water- 

 docks. 



The Dewey decimal system of classifying books in 

 a reference library is being adopted in America, and 

 modifications of it are widely used. The radio labora- 

 tory of the Bureau of Standards has extended this 

 method and applied it to the classification of books 

 and pamphlets in its library. In the Dewey 

 classification "radio" would be represented by 

 621-384. The number 600 denotes the class (useful 

 arts), the number 20 denotes the division (engineer- 

 ing), and the number i denotes the section (mechani- 

 cal). Similarly, 0300 stands for " electrical," o-o8o 

 for "communication," and 0004 for "radio." As the 

 library is a collection of matter dealing with radio, 

 the number 621-384 is denoted by R, and a further 

 number of three figures is added. For instance, R211 

 stands for "resonance methods of measuring wave- 

 lengths." R200 contains information on "radio 

 measurements and standardisation," Rio denotes 

 "theory," and Ri "statistics." An essential part of 

 the method is the alphabetical index. We look up, 

 for instance, "resonance methods" and find R211. 

 This gives us the number of the shelf in the library 

 on which the required books or pamphlets will be 

 found, the shelves all being classified in numerical 

 order. The books on the adjacent shelves also treat- 

 ing of cognate subjects can sometimes be usefully 

 consulted at the same time. The classification is 

 good and the alphabetical index very complete. We 

 missed, however, the word "thermionic." 



Messrs. C. Baker, of 24 High Holborn, W.C.i, 

 have issued a new edition (No. 72) of their catalogue 

 of second-hand scientific instruments. As is cus- 

 tomary in these lists, the items are grouped in sec- 

 tions according to the subjects with which they are 

 related. Twelve such sections appear in the list before 

 us, five of which deal with apparatus which may be 

 classed as physical. Section I., dealing with micro- 

 scopes and their accessories, includes particulars of 



