THE FARM HOLDING. L87 



Tanks or dams may be placed so as to water more than one paddock if 

 required. If the paddocks are large, however, it is better to place the 

 excavations as near the centre as possible, in order that stock may not have to 

 travel too far to water and will not tread down the grass so much going 

 to and fro. There must be a catchment area that will catch enough water 

 to fill the excavation in good heavy rains; a large area with a gentle grade 

 is preferable to too steep a catchment, as the latter carries too much soil 

 and rubbish down during heavy rains. See that the area is kept clean and 

 does not contain pigsties, sheep yards, &c. ; also, shade-trees should not be 

 left in the catchment, but rather below it, so that the excreta from stock 

 camping under them may not be washed into the tank and pollute the water. 



Very steep slopes are soon trodden down, mud and clay falls in, and the 

 shape of the excavation is spoiled. This applies to tanks that are not fenced 

 in and that stock are allowed access to all round. Sheep only should be 

 watered at these, and the slopes should not be less than 3 to 1. If made with 

 bullocks, ploughs, and earthscoops, they can be taken out at this grade all 

 round, but 3 to 1 is too steep for cattle and horses to water at. 



All excavations intended to be used for large stock should be fenced in 

 and access given at one side only, which is generally termed the roadway. 

 This should have a grade of from 4 to 1 to 5 to 1, and should be corduroyed 

 or stone-pitched — the latter is more lasting and safer in every way. This 

 can be done by making an excavation 7 or 8 inches deep and filling in with 

 large stones placed on edge, and all interstices tightly wedged with small 

 stones to an even surface and then blinded with gravel a few inches deep. 



Rule for Measuring Tanks. 



Add together the top area and the bottom area, together with four times 

 the middle area. Divide result by 6, and multiply by the depth. If the 

 measurements are in feet divide by 27, and the result will then be the size of 

 the excavation in cubic yards. Thus: — 



13,200 

 13,200 -r 6 = 2,200 

 2,200X10 (depth) = 22,000 cubic feet 

 22,000^-27 = 814-81 area of tank in cubic yards. 



If it is desired to find the size before sinking, the length and breadth oi 

 what the bottom will- be on completion can be obtained thus: — This tank has 

 the top measurements 60 feet by 80 feet long; depth, 10 feet; slopes on 

 three sides 2 to 1, and on one side (the roadway) 4 to 1; in the breadth, 2 to 1 

 for 10 feet=20 feet; this on either side=40 feet. This subtracted from 

 60 feet leaves 20 feet in breadth at bottom. In the length on one .side, 2 to 1 

 slopes x 10=20 feet; and on the remaining side, which is 4 to 1 by 10 

 feet deep,=40 feet. For both sides 60 feet to be taken off from 80 feet in 

 length of top, leaving 20 feet, thus 20 feet x 20 feet will be measurements of 

 bottem. 



