November 16, 1905] 



X.I TURE 



65 



pany, was built on the 4 feet 85 inch gauge, but when 

 the Government took over this line, and decided to take 

 in its own hands the construction of the railways, acting 

 on the advice of a strong commission, it dei ided to adopt 

 i feel 6 im hes as ihe standard gauge. That gauge 

 1, is been adhered to throughout South Africa with the 

 exi eption of one or two short branch lines, which are on 

 the 2-feet gauge, and at the present time a 2-feet gauge 

 line is in process of construction between Port Elizabeth 

 and Avonluur, a coast line, which will probably be even- 

 tually extended to Cape Town. The wisdom of construct- 

 in- a line such as this on a 2-feet gauge seems rather 

 doubtful, but the large bridges on it have been put up 

 <il >uch a strength and of such dimensions as would enable 

 a 3 feet 6 inches gauge to be adopted later on. Another 

 point on which the author laid great emphasis was the 

 system of surveying which it was necessary to adopt in 

 a country where Ordnance maps are at present unavail- 

 able. The colonial-trained surveyors are able to carry out 

 work with rapidity and with accuracy by the use of the 

 tacheometer only, which would be impossible in the hands 

 of surveyors trained only in our home methods. If a 

 country like South Africa is to be developed by railways, it 

 is obvious that the cost of construction must be kept 

 down to the lowest possible figure, and, therefore, tunnels, 

 heavy cuttings, and heavy banks must be avoided. All 

 the members of the visiting party who travelled over the 

 main lines in all the colonies during the visit of the 

 association were struck with the extraordinary surface 

 character and curvilinear meanderings of the railway lines, 

 although by this system of construction the actual length 

 of the lines has been in many cases increased, and the 

 I nibble speed at which trains can be worked has been 

 lessened ; nevertheless, when one compares travelling, both 

 as regards time and cost, on these lines with that in the 

 old days with ox or mule waggons, there is no doubt that 

 the wisest plan was to sacrifice, for the time being, possible 

 speed for economy in construction. The Cape lines, and 

 in fact all the lines which serve the Transvaal, suffer 

 from the same disability as the steamer lines which ply 

 between Europe and the Cape — heavy goods traffic is all 

 in one direction. No less than 80 per cent, of the goods 

 traffic on the Cape Government railways is in the shape 

 of up-country traffic ; this means necessarily a large 

 number of empty waggons returning to the coast, and 

 must inevitably increase freight charges. 



The section opened its proceedings at Johannesburg with 

 the president's address, which was devoted to irrigation. 

 The subject is one of such paramount importance to 

 South Africa that no happier choice could have been made 

 of a president for Section G than that of Sir Colin Scott- 

 Moncrieff. Naturally the examples selected by the presi- 

 dent for illustration of the problem of irrigation for 

 agricultural purposes were India and Egypt, although he 

 had also a good deal to say with regard to the system 

 in force in the United States and in Italy. It is to be 

 hoped that the information placed at the disposal of South 

 African engineers by this address will not fail to influence 

 the trend of legislation on this question in our South 

 African colonies. 



Sir William Preece gave an interesting account of the 

 present condition of wireless telegraphv, and his paper, 

 bringing all the information on this question up to the 

 most recent date, was a welcome contribution to the trans- 

 actions of the section. Sir William Preece has on previous 

 occasions contributed papers on this question to the 

 section, and has kept the section well informed of the 

 gradual progress in the evolution of wireless telegraphy 

 as a practical mode of communication. 



Prof. Perry's paper on the accidental breakage of wind- 

 ing ropes in mines concluded the first day's work at 

 Johannesburg. In this paper certain examples were 

 worked out in full, and in an appendix to the paper the 

 whole of the mathematical treatment of the problem was 

 given by the author. 



The second day's proceedings were opened bv Mr. 

 Hammond with a paper on electrical power distribution 

 for the Rand. After alluding briefly to the present ten- 

 dency at home, and at such situations as the Niagara 

 Falls, to construct large central supply stations, the author, 

 referred to the fact that he was surprised to find that this 



problem had not yet been taken up on the Witwatersrand. 

 Two points were, therefore, discussed in the paper — one 

 was whether the working of the mines could not be 

 cheapened by the extended application of electrical power, 

 and the second, as a corollary, whether bU ch electrical 

 power could not be more economically produced by a 

 central station rather than by each mine, or group of 

 mines, laying down its own plant. In colliery work in 

 Great Britain there is, and has been for the last year 

 or two, a steady growth in the application of electricity 

 to haulage and other work in the coal mines, and the 

 author advocated the adoption of electrical winding for 

 the Rand mines. He also pointed out that a considerable 

 increase of efficiency would be obtained by the abolition of 

 the surface compressed-air plant, and by the introduction 

 of electrically driven compressors, placed underground near 

 the actual workings. Mr. Hammond showed that the 

 total requirements of the Rand mines worked out at a 

 very high figure of horse-power hours (400,000,000), and 

 he proved by further figures that a central power station 

 would thus have a very favourable load factor. Assuming 

 a diversity factor of 60 per cent., and a 20 per cent, loss 

 in distribution and transformation, he estimated the plant 

 capacity at the central station would be 60,000 kilowatts. 

 Basing his further calculations on these figures, the author 

 then proceeded to work out fully the costs of generation 

 and distribution, the revenue which could be expected, 

 and the corresponding financial results. In concluding 

 his communication, which was one of great value, Mr. 

 Hammond referred to the case of the well known central 

 power station at Newcastle-upon-Tyne, and expressed the 

 opinion that if on the river Tyne, where coal was avail- 

 able in large quantities at very low rates, it paid to 

 displace steam power by electric power, still more so would 

 it pay on the Rand. 



Mr. Dew read a short paper on water-power plants, 

 Pilgrim's Rest, Transvaal. In this paper the author gave 

 a list of plants in actual operation with the horse-power 

 developed, the type of prime mover, quantity of water, 

 and head, and dealt with a number of points of special 

 interest in the running of such plants. 



On the Friday, the last day the section met, the first 

 paper was by Mr. C. W. Methven, on South African 

 harbours. This paper was one of great importance, and 

 must have involved an immense amount of work in its 

 preparation. Practically a complete history of the harbours 

 which have been built up round the South African coast 

 was given. As the author pointed out, there is a remark- 

 able absence of deep-water indentations forming natural 

 harbours between Cape Town and Delagoa Bay, and 

 therefore all the harbours have had to be artificially 

 created. After giving a brief account of the Table Bay 

 works, and the extensions now being carried out by Mr. 

 Hammersley Heenan, the author referred to the Algoa 

 Bay works, and the remarkable stride which had been 

 made within the last few years in the commercial pros- 

 perity of this harbour, in spite of the difficulties due to 

 its exposed condition and the heavy seas which frequently 

 make approach almost impossible. Mr. Methven then dis- 

 cussed very fully the formation and treatment of sand-bars 

 at the mouths of the rivers and lagoons on the south-east 

 African coast, which render the construction of harbours 

 and their maintenance such a difficult engineering problem. 

 Another valuable paper taken at this sitting was one 

 by Mr. C. D. H. Braine, on irrigation in South Africa, 

 dealing with the important question of the duty of water 

 used for irrigation purposes. The author stated that there 

 was very little information on the subject as regards 

 South African practice, and that therefore irrigation 

 engineers in South Africa had to be guided to a great 

 extent by experience in other countries, such as America, 

 Spain, India, &c. He pointed out how unskilled irriga- 

 tion frequently means a waste of from 25 per cent, to 

 50 per cent, of water, and thai many crops were actually 

 impaired by excessive irrigation. For South Africa he 

 was of opinion that the duty actually used on the land 

 could be safely taken at the rate of 285 acres per cubic 

 foot of water per second, and he quoted statistics from 

 other countries to show that this was a reasonable allow- 

 ance. To show the value of irrigation in South Africa, 

 the author gave figures as to increase in land values; 



NO. l88 1, VOL. 73] 



