72 IRKIGATION FARMING. 



1283 feet by 641.05 feet, holding 23,500,000 cubic feet 

 of water. The cost is $37,617, which at 7 per cent per 

 annum interest would be equal to an annual charge of 

 $2,633, or $112.21 for a million cubic feet, without any 

 allowance for maintenance. This, at the area value of 

 ten acres for a million cubic feet, would irrigate 235 

 acres at a cost of 811.22 an acre, which represents the 

 total cost for all time to come. 



At some sites it might be necessary to pump water, 

 and under the conditions likely to be met in practice, 

 where the work will be done in isolated localities and 

 confined to 90 or 120 days' work in the year, while the 

 interest on the cost of the plant \vill have to be charged 

 fora whole year, the cost will average about fifteen cents 

 a million cubic feet to the foot raised, or about $15 to 

 raise that amount of water 100 feet. This estimate is 

 made on the basis of coal costing $5 a ton, and an average 

 engine of 50-horse power. If the water is pumped dur- 

 ing the whole year, the cost will be reduced to two-thirds 

 of this amount. AVith a depression having natural sides 

 in place, and where not more than one-fourth of the cir- 

 cumference would have to be constructed, the cost would 

 be proportionately less. 



Damming a Stream. The chief cause of failure 

 in dams of all kinds is the faulty construction of the 

 foundation. Dams should be made of timber or stone. 

 For a safe and simple form of timber dam the foundation 

 should be rock or a hard pan of gravel, and the mudsills 

 on the lower tier should be bedded in broken rock, 

 pounded down firmly with a fifteen-pound sledge. The 

 sills are saddled, and the cross ties laid upon them are 

 notched to rest upon the suddlrs, ;i :d two-inch- pins 

 should be put through both of the logs. Whnv the 

 foundation is shelving rock, one-and-n-h;il!' inch iron 

 pins should be put down into tin- mcl\. ;it 1< i ' ;i in 

 prevent sliding. But the sliding force is ;>l;.;o.^ n<, utral- 



