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To CALCULATE CONTEXTS OF TANK. 

 An ordinary tank is a prismoid, its horizontal sections 

 rectangles. The volume of any prismoidal tank may be found by 

 the following rule : To the top area add the bottom area and four 

 times the middle area. Multiply the sum by the height one-sixth 

 of the product is the volume. 



X.Ii. The easiest way to find four times the middle area is to 

 multiply the sum of the top and bottom lengths by the sum of the 

 top and bottom widths. 



Example. A prismoidal tank is eight feet deep. The top 

 length is 120 feet, its bottom length 80 feet ; its top width is 100 feet, 

 its bottom width, 60 feet. Find its volume ? 



120 X 100 =12,000 



Sox 60= 4,800 



200 x 160 =32,000 



48,800 



6 | 390,4 

 3 | 65,067 (nearly) 

 9 | 21,689 



2,410 (nearly) 

 Answer. 2410 cubic yards (true to the nearest yard). 



WELLS. 



It is always advisable to test the country for well water. 

 Unfortunately much of the underground water in central Australia 

 is often salter than the sea, but brackish water is often obtained, 

 and on this sheep do extremely well. I have known sheep 

 thrive on water so full of salt and other minerals that 

 horses would not drink it though almost dying of thirst. 

 Where a well of drinkable water for stock can be struck it is a great 

 relief to the pastoralist. The tube wells us d in sinking for artesian 

 water in Queensland should be used, as this mode of sinking for 

 water is cheaper and more quickly performed than the ordinary 

 mode of well sinking. In some waters that is quite healthy 

 for sheep, there are chemicals that corrode iron pipes in a 

 very short time. In that case some mode of coating the metal 

 with a protective substance must be employed. I know a piece of 

 country in which the soil in low situations is full of such chemicals, 

 and the rabbit netting sunk in the ground rotted within twelve 

 months. A coating of coal-tar and kerosene, melted together, 

 proved an efficient protection both for wire netting and for the 

 pipes that were used for carrying the water to drinking places. 

 When the water in a tube well does not reach the surface a wind- 

 mill pump with a couple or more of 400 gallon tanks will furnish a 

 good supply of water for stock. 



