1HL IRRIGATION AGL. 32r 



and would have cost a great additional sum. I refer to the find of our 

 granite right here in the bed and along the banks of the river. I had 

 calculated on having to ship the greatest part of the material for 

 stonework. I was aware that a certain kind of granite was to be 

 found in this vicinity, but did not believe that it would be hard enough 

 or of sufficiently good quality to be available. When we commenced 

 excavating there were unearthed what apparently seemed inexhaus- 

 tible quarries of as fine a granite as could be found anywhere on the 

 globe. This saving in time and money can scarcely be overestimated; 

 for not only is high-quality granite expensive, but the difficulty of 

 transportation would have entailed enormous outlay, not to speak of 

 irritating and expensive delays while waiting for material. 



The total extent of the dam is one mile and a quarter, of which one 

 mile and an eighth of the foundation is finished. Temporary dams, 

 enabling the remaining section to be put in, are now carried across 

 the channel. Pumps for getting in the permanent dam foundations 

 will be started immediately. The whole of the granite masonry re- 

 quired for the dam is cut and ready to be laid in place. The parapet 

 alone remains to be prepared. The portion of the dam remaining to 

 be built is that across the well-known western channel. This will be 

 the most difficult part of the entire work, but, profiting by experiences 

 gained thus far, I feel confident that I can cope with any problem that 

 may arise. 



The first great difficulties to contend with were those connected 

 with the foundations of the dam. Although advantage was taken of 

 Ihe numerous large rocks stretching across the river, it was found 

 that between them were serious faults or fissures, in which it was 

 necessary to go down great distances before arriving at a sound 

 bottom. Speaking generally, in many places the depth of the founda- 

 tions amounts to twice the height of the superstructure. The founda- 

 tions have now been completed to within a distance of about a hundred 

 and fifty yards of the west bank. Each portion of the bed of the river 

 has had to be dammed and cleared of water before the work could 

 proceed, in order that it should be perfectly sound and lasting. This 

 has, of course, caused an immense amount of labor. 



There are altogether one hundred and eighty sluices. On the 

 shore ends these are in a double tier, but they are single in the central 

 portion. These will, of course, be opened and shut by hydraulic 

 power. The upper sluices are not carried to the actual top of the 

 dam, which would thereby be weakend, but are openings in the work 

 with a continuous line of masonry above them. The locks are to be 

 erected on the west or uncompleted side, and will be of immense 

 ^strength and adequate capacity. Many of the sluices where the pres 



