TANK. 



constructed of an oblong shape, of 

 brick well cemented, with one or 

 more divisions, and capable of con- 

 taining at least ten times as many 

 hogsheads as liiore are heads of cattle 

 on the farm. They are vaulted over, 

 having a small a[)crture, in uiiieh a 

 pump is placed, sullicient to allow a 

 man occasionally to clear out the sed- 

 iment when the li([uid has been pump- 

 ed up. The best shape to contain a 

 large quantity in the smallest sjtace 

 would be like those before descrii)ed ; 

 but they cannot conveniently be made 

 sufficiently large, and a cubical fonn, 

 or, rather, that of several cubes in 

 succession, is preferred. A tank for 

 a farm of 200 acres of arable land 

 should be 15 feet wide, 15 deep, and 

 45 long, giving three cubes of 15 feet, 

 or a cavity capable of containing up- 

 ward of 10,000 cubic feet of liquid. 

 In this tank the urine is diluted with 

 water to prevent too rapid decompo- 

 sition, and also to retain the ammo- 

 nia which is formed ; for which pur- 

 pose gypsum and sulphate of copper 

 are sometimes put into the tanks. 



" If the soil be not sandy, clay will 

 answer, instead of mortar, to con- 

 nect the brick-work, and a plastering 

 of lime or cement will be sufficient to 

 keep out the worms ; hut in very 

 porous soils the bottom and sides 

 must be puddled, to keep in the litjuid; 

 and it may be advantageous to build 

 the walls in cement altogether. The 

 liquid from the yards and stables is 

 carried into the tank by a main drain 

 constructed of brick or stone, and 

 which receives a number of smaller 

 drains from every part of the yards 

 and cattle sheds. Thus the litter in 

 the yard is always dry, and none of 

 the richness of the manure is lost by 

 evaporation. 



" Sometimes the tank is vaulted 

 like a cellar under the cow-house and 

 stables, which are washed out twice 

 every day, and all the dung and wa- 

 ter are swept into a cess-pool com- 

 municating with the tank. Thus a 

 very diluted but rich liquid soon fills 

 the lirst division of the tank : a sluice 

 is then shut, and the next washings 

 run into a second division, and when 



that is full, into a third. In the mean 

 time the contents of the first tank 

 have undergone a certain fermenta- 

 tion, by which the caustic ammonia 

 first evolved has become mild and 

 impregnates the water. It is then 

 in a fit state to be carried on the land 

 in tubs or water-carts. When prop- 

 erly diluted, it accelerates vegetation 

 in a surprising degree ; but if jjut on 

 fresh, it burns the grass or any ve- 

 getable it touches, because the am- 

 monia is in a caustic state. If a cow 

 drop her urine in a field in a hot 

 sunnxier's day, all the grass it has 

 touched becomes yellow and is burn- 

 ed up ; but if the same happen in 

 rainy weather, the spot soon becomes 

 very green, and the grass luxuriant ; 

 because, in this case, the urine is 

 amply diluted and its caustic nature 

 corrected. Those who live near gas 

 works may collect the ammoniacal 

 gas water in a tank, and, by the ad- 

 dition of sulphuric acid in very small 

 quantities, they may produce a very 

 fertilizing liquid, which will stimulate 

 vegetation, and be a very good ma- 

 nure. 



" The necessary concomitant of a 

 tank, whether for water or manure, 

 is a water-cart, that is, a large cask 

 put upon wheels to bring water from 

 some distance. When there are no 

 means of bringing water in pipes, a 

 water-cart is quite indispensable. It 

 is simply a cask placed on the frame 

 of a cart, with a plug-hole in the end 

 or lower part, from which the water 

 may be let out by a cock, or drop on 

 a flat board or into a bucket with 

 holes, so as to spread it about. The 

 plug-hole is shut by a valve inside, 

 which can be opened by means of a 

 string, the pressure of the liquid 

 keeping it close to the plug-hole. 



" Many of the artificial manures, 

 of which a number have been lately 

 proposed, would make excellent li- 

 quids by merely mixing them with 

 water in a tank, and allowing a cer- 

 tain degree of fermentation to take 

 place. Thus nothing is lost, and all 

 volatile substances are taken up by 

 the water. The soluble portions are 

 dissolved and the earthy matters dif- 



775 



