212 NEW BOOKS. 



TRANSACTIONS OF SOCIETIES. 



South African Institute of Electrical Engineers. — Thursday, 

 October 19th: Mr. J. H. Rider, V.P.I. E.E., President, in the chair. — 

 " The troubles of cables "" : A. E. Gibbs. The author gave an account 

 of some of the faults and other troubles that he had experienced in 

 connection with cables, and described the methods for locating these. 

 In this connection he discussed the advantages and disadvantages of 

 lead covered and bitumen covered cables, and the various methods of 

 laying and joining. — Thursday, November i6th: Mr. J. H. Rider, 

 V.P.I. E.E., President, in the chair. — "Fixation of atmospheric nitrogen 

 by electricity " : Dr. W. Glucksman. The importance of the nitro- 

 gen problem and its special importance for South Africa, where nitrogen 

 is needed for agriculture and nitrogenous explosives for the m.ines, was 

 lirst emphasised, and after referring to the principles of hxation methods, 

 the author briefly dealt with the several processes introduced by Bradley, 

 Lovejoy, Kowalsky, Moscicky, Birkeland, Schonherr, and Pauling. 



ChemicaLj Metallurgical and Mining Society of South Africa. — 

 Saturday, October 21st : Mr. H. A. White, Vice-President, in the chair. — 

 "Notes on high duty gravity Stamp Mills": P. N. Nissen. A des- 

 cription of recent improvements in the design of gravity stamp mills, 

 with illustrations of the capabilities of the improved stamps and of the 

 advantages to be derived from their installation. — Saturday, November 

 i8th : Mr. E. J. Laschinger, Vice-President, in the chair. — "Accidents 

 in Transvaal Alines " : J. Chilton. The author said that the Trans- 

 vaal Mines have the highest accident rate of any mining district in the 

 world, and that on every full working day in 1910 three persons were 

 killed and six injured. The Transvaal mines death-rate was 31.5 per 

 million tons raised, as compared with 4.5 in England. Accidents due 

 to defective plant were diminishing, but those resulting from inherent 

 danger in the work itself were increasing. More accidents resulted from 

 falls of ground than from any other cause, and it has been a steadily 

 increasing cause for the last seven years. The author concluded by 

 advising the appointment of roof inspectors and the systematic timbering 

 of stopes. — " Practical applications of the specific gravity ilask '" : H. 

 Stadler. The author showed how a wide-mouth open flask, with a true 

 ground edge, could be of great practical use in (i) determination of 

 specific gravity of .solids, (2) determination of specific gravity of pulp, 



(3) determination of weight percentages of dry solids and water in pulp, 



(4) tonnage measurements of total pulps and of dry solids in pulps, 

 and (5) relation of flowing quantities in classifiers. 



South African Institute of Engineers. — Saturday, November 25th: 

 Mr. F. H. Davis. President, in the cliair. — " Notes on cams for Stamp 

 Mills " : G. i\I. Adams The author showed that the stresses on the 

 cam shaft could be greatly reduced by increasing the period of initial 

 acceleration, that it would probably be imperative to employ means of 

 reducing those enormous stresses owing to the tendency to use heavier 

 stamps. Methods were given of arriving at rules and formuL-e for 

 determining the proper strength of cam shafts, bearings, etc. 



NEW BOOKS. 



Fyfe, H. Hamilton. — South Africa io-day: ZK'ifh an <iccouiit of 

 modern Rhodesia. London: G. Bell & Sons, 191 1. Demy 8vo., 

 illus.. gs. 



Kassner, Theo. — My journey from Rhodesia to Egypt, indnding an 

 ascent of Ruzvenaori and a short account of the route from 

 Cape Tozcm to Broken Hill and Lado to Alexandria. London: 

 Hutcliinson & Co., 1911. pp. xiv, 310. 9 in X 5i in. Maps 

 and illus. 12s. 6d. 



Christy, Cuthbert. — The African rubber industry and Fnntuniia 

 clastica. London: J. Bale, Sons & Danielson, igii. pp. xvi., 

 252. 9 in X 5^ in- Maps, illus., and diagrams. 12s. 6d. nett. 



