112 



TRANSACTIONS OF SOCIETIES. 



South African Institute of Electrical Engineers. — Tluir^day, 

 April 15th: B. Price, President, in tlie chair. — "Prof. Bcraonic's chair for 

 ilic treatment of obesity and heart trouble": W. H. Perrow. The 

 ol:)ject of the chair is to impart to the patient muscular contracticns similar 

 to those produced by walking". The muscular contractions are set up to 

 the same number as the beats of a metronome provided with dipping 

 contact in mercury, and capable of being set to any required number of 

 beats per minute. 



Thursday, May 20th : B. Price, President, in tlie chair. — "Fuiidaiueiital 

 hrinciflcs involved in the lay-out of a iclei-hone exel!an,c;e systeiii": T. 

 Pearson. The paper was devoted to a description of ground-work 

 t'.etails, ^.,i,^. the consideration of a central location, the determination of 

 a suitable telephonic centre, and tlic eslal)lis]imcnt of subsidiary ex- 

 changes. 



Thursday, June i/th : B. Price, President, in tlij chair. — "Water 

 f^ozi'er /^lanls: leith special reference to the power plants of the Rezende 

 Mines. Ltd.. PenlwAouiia, Sontiiem Rhodesia" : El. "Wragg. The 

 I'mtali River enters the Penhalonga Valley over a diorite dyke with a 

 free fall of 3S0 feet. The water is led ah ng a 1,500 yard flume with a 

 capacitx' of 200 ft. per minute, and drives double 40-inch Pelton wheels. 

 This Umtali River electrical scheme is m good order after 15 years' con- 

 tinuous work Seven miles to the north flows the Odzani River, in con- 

 nection with which two power schemes havt been installed. In scheme 

 No. I. 2,400 cubic ft. of water per minute are carried along a flume on a 

 trestle bridge to three Pelton wheels. Scheme No. 2 takes in the water 

 discharged from No. i Station, and the two Odzani systems together supply 

 25 motors with an aggregate of 1,600 h.p. 



South African Society of Civil Engixeers. — Wednesday, ]\Iay 12th: 

 R. W. .Alenmuir, A.jM.I.C.E., Vice-President, in the cliair. — "' S'oles on rall- 

 "djay construction in the Katanaa, Belgian Congo": _E. A. Browning. 

 A general description of the country and its typical features was given, 

 together with an account of the labour conditions. The construction of 

 the line had to be preceded by making a clearing through the forest, and 

 a special feature of the earthworks was that necessitated by the enormous 

 size of the ant-hills, which ranged up to 20 ft. in height, with a diameter 

 of 60 ft. at the base. The removal of one such ant-hill involved the 

 excavation of 1,200 tons of earth. 



Wednesday, June 9th: R. W. ]\[cnmuir. A.^I.I.C.E., \'ice-President, 

 in the chair. — •" L'jiit stresses in rein forced concrete: from a railzi'ay engi- 

 neer's point of view." W. H. Clark. The author suggested that in 

 testing the strength of concrete the stresses to be allowed for purely 

 static loads should be determined, and that live stresses should be reduced 

 to that basis by impact allowance. He proceeded to discuss what 

 impact allowance added to the live load, should be considered 

 as reducing it to an equivalent dead load. It was considered that 

 reinforced concrete will be more used for railway Avorks than in the 

 past, though probably not as extensively as had once been imagined. — 

 ■■ Tlie parabolic reinforced cov.crete arch " : A. H. Henderson and 

 Prof. A. E. Snaps. The use of the parabolic form of arch considerably 

 simplifies calculations. Various conditions were considered generally and 

 in particular applications. 



Chemical, INIetallurgical and IMining Society of South Africa. — 

 Saturday, May 22nd: Prof. G. H. Stanley, A.R.S.M., M.I.M.E., :M.I.M.M., 

 F.I.C, President, in the chair. — " Xotes on the practical testing of ivorkinq 

 cyanide solutions " : E. H. Croghan. The author showed that consider- 

 able diversity of results might be obtained in testing working cyanide 

 solutions in consequence of lack of uniformity of practice in regard to 

 the end point of titration. He suggested a discussion as to the most 

 suitable methods for uniform adoption, and quoted his own practice in 

 such cases. 



