TKANSACTIONS OF SU(II:TII:.S. 629 



involved no engineering works of any magnitude except the crossing of 

 the Orange River at Aliwal North. Tliis hridge comprises six spans of 

 125 feet eacli. 



Wednesday, -May ytli : R. W. .\Knnniir. M.I.C.E., President, in the chair, 

 ■■ ll'liitc labour '' : G. Whitehouse. The author's object was to show that 

 on unskilled work on railway construction the white labourer is able to 

 compete successfully against the native labourer under the conditions of 

 use which have hitherto been in practice. White labour, however, cannot 

 be successful in South Africa as long as it is considered an experiment, 

 given on philanthropic lines to the unemployed in times of stress and 

 poverty, and looked on as charity by the charitable, and as relief work 

 by the labourer. The object at which this experiment aims should be a 

 certain hxed idea of white employment everywhere. — " Small power 

 staiioiis. z^'itii special reference to the Jl'orcester hydro-electric scheme'' : 

 Prof. H. Bohle. The great distances which separate municipalities in 

 South Africa make it necessary to erect power stations at almost every 

 place where electric light is desired, necessitating large capital expenditure 

 and high charges. The source of Worcester's water supply lies six miles 

 away, up in the tnountains. The installation consists of two 60-h.p. Pelton 

 wheels running at r,oco revolutions per minute. The cost of the scheme 

 was nearly £15,000 and to make it self-supporting the annual income 

 should reach about £2,400. 



SofTH Africa:^ Institl-tion of Engineers. — Saturday, April 14th: B. 

 Price, M.I.E.E., A.M.I.C.E., President, in the chair. — "Xofes on dust pre- 

 vention in mines": .A. C Whittome and J. H. Yeasey. The authors 

 laid down that tlie allaying of (hist and gases and the improvement of 

 ventilation — both as regards quantity and temperature of air — snould De 

 treated as one subject. The water used for allaying dust and gases, and 

 for cooling the air can best be atomised by the use of compressed air. 

 The control of all the operations of dust and gas allaying, as well as 

 the regtilation of ventilation should rest with one official. Miners should 

 be unable to regulate the quantities of air and water used in water blasts. 

 Dust and deleterious gases should be removed from the air as soon as 

 possible after they are generated. Atomised water is the best means for 

 remov.ng dust, and al! deleterious gases except carbon mon-oxide, from 

 air ; therefore the vvhole of the mine workings should be filled with 

 atomise-d water as soon as it is possible after blasting. The " deadly " 

 dust is invisible; therefore continuous means of removing it from the air. 

 and nf ascertaining the daily condition of the air itself should be provided 

 at selected i)oints in the main air-ways. Watering down of faces and 

 walls should lie done with at(jmised water; only heaps of rock should have 

 streams of water directed upon them. The mechanical ventilation of dead 

 ends should l:e i);i a system by which induced currents could be directed 

 to the working faces .whilst foul air would be exhausted from the working 

 places. There should be a simple and immediate indication as to whether 

 the water-blast has been put into operation h\ the miner responsible. This 

 check should be available as soon as the miner is out of the mine. The 

 owners of those mines — and the imdergrotind employees therein — in 

 which it can be shown that there is no dry dust during working shifts 

 ■-hould be relieved from all contributions to the Phthisis Compensation 

 Fund. I'lie authors concluded with a descri]ition of the "Apex" water 

 blast. 



SoLTH Afrk AX l.NSTiTLTE OF Elfctkkai. l\N(;iNKERS. — Thursday, April 

 19th: \\". \\. Perrow. M.I.E.E., President, in the chair.— "Notes on three- 

 phase and Ward-Leonard zvindi)ig equipments" : A. L. Ballard. No 

 attempt has thus far been made to state definitely the limits between which 

 one .system has advantages over the other. Cienerally speaking the three- 

 phase equipment will !)e found economical on straightforward winds of 

 moderate depths and weights, but for greater depths than 3,000 ft., probably 

 up to ^.000 feet there v.ill not be much to choose between the two systems, 

 whilt alcove this dt-ptli the advantage will be with tlie Ward-Leonard 



