J 52 THE COPPER FIELD OF NAM AQUALAND. 



In conclusion, I wish to thank Mr. Botha for help in copy- 

 ing the original, and Mr. T. B. Herold for correcting some pas- 

 sages which I had not clearly understood. 



{Read, July 4, 19 17.) 



TRANSACTIONS OF SOCIETIES. 



South African Institute of Engineers.— Saturday, June 30th: B. 

 Price, M.I.E.E., A.M.I.C.E.. Past President, in the chair. — " Notes on the 

 support of the underground ivovkings in the mines of the Rand'": 

 P. Cazalet. Methods of work, which have been suitable in the past 



for the support of hanging walls, are so no longer on many mines, (i) 

 because the workings of adjoining mines are practically assuming the 

 character of continuous excavations, at most only partially supported over 

 long distances, and (2) on account of the increasing depth of the work- 

 ings. Sand-liUing had been introduced with the greatest benefit, but on 

 a large scale only in a few mines, and that sand-filling alone will suffice is 

 unlikely. Four methods of supporting hanging wall therefore remain, 

 viz., (i) the packing or stowage of waste rock, (2) the square set method 

 of timbering, (3) the use of round timber for props, stalls, and pigstyes, 

 (4) the packing of ore actually broken at stope faces. The last rnethod 

 is, in the author's experience, the only one whicli entirely meets the re- 

 quirements. — "Systematic packing underground at the Ferreira Deep 

 Mine" : G. Hildick-Smith and R. Selby. The nature of the hang- 

 ing wall, originally a naturally strong quartzite. had completely changed 

 throughout the mine, and had become very broken and dangerous, causing 

 stopes to cave and shafts to give trouble. The mine had been saved by 

 resorting to systematic packing, in conjunction with the removal of pillars, 

 which were replaced by packs. The various methods of packing found 

 to be most efficient were described and illustrated. 



Saturday, July 14th: G. M. Clark, M.A., A.iM.I.C.E., President, in the 

 chair. — "Suction gas production from South African bituminous coals": 

 F C. Sturrock. and E. J. Way. The authors gave an account 

 of some of their experiences met with, and some of the results obtained 

 in the practical application of South African fuels to one of the latest gas 

 producers of the suction type. Some of the principal difficulties that 

 have had to be overcome in connection with diflferent makes of bituminous 

 plants were discussed, and the improvements which their experience had 

 suggested to the authors were referred to — " Notes on tests of timber 

 pigstyes": H. C. Hilton. In the Transvaal gold mines the natural 

 pillar has to a large extent been displaced by timber stopes in the form of 

 pigstyes,, and the latter, if unfilled, appear inefficient, (i) because of the 

 small proportion of the timber that is called upon to withstand any strain, 

 and (2) because those parts which take the strain carry it in the direction 

 in which timber is weakest. The tests described by the author were made 

 in order to ascertain the correctness of these assumptions, and the most 

 efficient form of pigstye. 



Saturday, nth August: G. M. Clark, M.A., A.M.I.CE-, President, in 

 the chair. — Presidential Address : G. M. Clark. The address dealt 

 largely with the subject of education as it affects engineers. Tech- 

 nical education was specially referred to, and free education in the higher 

 stages, as well as in the lower, advocated. The relationships and func- 

 tions of an Institution of Engineers were also shortly discussed. — 

 " Furt'er notes on the collapse and recovery of the Central Shaft at the 

 Bantjes Consolidated Mines." G. Hildick-Smifh. A description of the 

 methods used in reclaiming three compartments of a collapsed shaft, with 

 statements of costs. 



