T K A X S . \ C'l" I () N S < ( I' soil Kl I KS. 373 



Saturday. Xovcnur iitli: I'.. I'rioi.', M.l.rM'., A.M. I.C.I-"., I'rc.sident, 

 in the cliair. — " Xolc on hollcii limlh-r joints": W . Alexander. In tlic 

 case of a tension joint, consi.sting of a middle piece of tiniljer and two 

 side pieces, the distribution of the transverse pressure of the wood on 

 the l)olt was briefly discussed, and forniuhc were obtained (i) for the 

 thicknesses of the side and middle ])ieces and tlie diameter of tJie bcilt, 

 and (J) for the stren.uth of the bolt per joint. 



Saturday, Deceml)er otb : B. Price, AI.I.E.E., A. M.I. CI-:., President, 

 in the chair. — "Boiler house operation and maintenance: zvith special 

 reference to the Rand Pozcer Companies' Plant": T. G. Otley. and V. 

 Pickles. The methods of boiler house operation and m.iintenance 

 adopted at P>rakpan. Simmerp'Ui. Rosherville, and Vereenitiins^ were 

 described, and the results of efficiency tests were set out. 



Saturday, January i^tli; I'.. Price, .M.l.E.E., A.M.I.C.E.. President, in 

 the chair. — "Recent devclopinenls I'f the ll'hifing hoist as applied to 

 deep winding": B. Gray, and J. Whitehouse. Experiments and deve- 

 lopments carried out at tlie Village Deep Mine in winding with Whiting- 

 Hoists were described, and an account was .given of the winding plant 

 originally employed, and (;f the steps which led up to the conditions at 

 present existing. The possibilities of applying the imjjroved system in 

 the future to deep winding were discussed. 



Saturday, Eebruary igth : P.. Price, M.I.E.E., A.M.I.C.E.. President, 

 in tlie chair. — " The deterioration of Curtis Rateau Turbine blading'': A. 

 Fen-wick. The author supplied information and placed on a record data 

 summarising his experience, with regard to the behaviour of certain 

 materials used in turbine blading, gained during the last six years in 

 operating and maintaining the turbine plant of the Rand Power Com- 

 panies. All necessary particulars regarding the design of this plant were 

 included. 



South African Institute of Electkic.al Encinkkus. — 

 Thursday, Xovember i6th : Professor W. Buchanan, M.LE.E., President, 

 in the chair. — " Electrical system of the Rand Power Companies, with 

 special reference to methods of operation and experience '" : B. Price. 

 The lay-out and characteristics of the electrical portion of one of the 

 largest power schemes of the present day was described, and connnented 

 on. in the light of experience gained on that scheme by the author during 

 a period of seven years. 



Thursday, December 21st: Prof. W. P>uchanan, M.l.l'lE., President, 

 in the chair. — " Some notes on efficiencies and costs of steani and electric 

 zvinding plant": H. W. Clayden. The relative efficiencies and power 

 cost of three winders — two electric and one steam — working on mines 

 under the control of the General Mining and Finance Corporation were 

 dealt with. It appeared that, for surface winding, given the same capital 

 cost for installation, and the present ruling high power rate on a low- 

 load factor, steam is the cheaper power with a load factor below 35 per 

 cent., and electricity above ,^5 per cent. Erom figures obtained on hoists 

 on the group -of mines the above conclusion appears to hold good for 

 hoists up to (Soo h.p. — " Comparison of Ward-Leonard and Three-Phase 

 irinding Systems": S. E. T. E-wing. The conclusions reached by the 

 author were that for shaft-sinking either type is equally effective on all 

 points at approximately equal capital cost; that for rock-winding from 

 one level, the capital cost is lower in the case of the alternating current 

 system, and both systems afford equal safety and ease in handling; where 

 even running is secured liy means of tail ropes, relative economy depends on 

 the frequency of winding, but in absence of tail ropes and for rock- 

 winding from several levels, for raising and lowering men, lowering 

 supplies, and dead slow winding the three phase winder in each case 

 involves lower capital cost, but the Ward-Leonard is more economical and 

 easier to handle. 



Thursdav. Eebruarv 22nd: W. 1.1. Perrow. M.I.E.E.. President, in the 

 chair.— Presidential address: W. II. Perrow. The early history of tlie 



