Presidential Address. — Section C 345 



teet in length with a draught of 35 to 40 feet. Here in Cape Town 

 Harbour, which should have been one of the iinest harbours in the 

 world, we have an object picture of want of foresight and tinkering 

 for present needs. l)ut there is hope in the fact that those now in 

 authoritv have recognised the inadequacy of the present accommo- 

 dation, and are prepared with a scheme of proper scope. In every 

 fast growing country it is necessary to lay out a scheme prt)viding 

 for very great expansion, and with a fitting sense of economv to 

 carry out from time to time only such portions of that scheme as are 

 warranted by the probable trade of the immediate future. 



When it is rememl)ered that at the old established port of J/iver- 

 pool. in Lancashire, the rate-paying tonnage of vessels increased 

 from 6,089,543 tons in 1875 to 10,021.725 tons in 1900, there is 

 godd reason in anticipating a much larger percentage of growth in a 

 country that is in the first stage of development. The handling of 

 tonnage on a large scale, especially dealing with coal, ore, or grain, 

 has led to the use of very special electric cranes of the gantry or 

 cantilever class. The " Brown Hoisting Machinery Compans ,"' of 

 Cleveland. Ohio, has erected machines on the Great American 

 Lakes which handle nearly 20 million tons a year, and have brought 

 the cost of handling down to an extraordinarily low figure. The 

 " Temperley Transporter Company." in the United Kingdom, has 

 done excellent work in providing transporting and hoisting plant, 

 and special ap]iaratus for unloailing barges into trucks or into ware- 

 houses, and in (ierman) ingenious coal conveying plants have been 

 erected by the '' Benrathe Maschinen Fabrik," and the " Allgemeine 

 Electricitals Gesselschaft." of Berlin. For working cranes electricity 

 seems to possess advantages over steam or hydraulic cranes, or 

 Clones worked by compressed air. The ideal crane shouiii start its 

 load slowly, accelerate to a high speed, and slow down quickK to a 

 .standstill. The electric crane meets these requirements better than 

 an\ other. The further advantages of electric cranes are: (i) That 

 the i^ower consumed is proporional to the work, (2) and that the 

 power can be conveyed to a greater distance more easily and at a 

 cheaper cost than l)y another means ; (3) the electric crane has a 

 total efficiency of 72 per cent., whereas the efficiency of hvdraulic 

 cranes is rarely more than 50 per cent. The s])ecial svstems of 

 transportation alluded to have hardly been wanted here as vet, as 

 they are only economically used when a large tonnage has to be 

 handled for a short distance with great speed and at a low cost. 

 At the Diamond Mines the problem is to mine the blue at the lowest 

 cost, to haul it to the surface from a total depth of 1.200 to 1.500 

 feet (and we may note that 600 tons of l)lue are hauled daily up one 

 shaft) to carry it thence by endless haulage to the floors on the open 

 veld, where it is exposed to weather and disintegration, and from 

 thence to transport it after weeks of exposure to the washing machines, 

 and thence to the pulsating machines, where the diamonds are caught 

 and separated by grease and other special contrivances. An interest- 

 ing development is taking place now at the De Beers Mines, where 

 a central electric power station is being erected with all the a(' 



