TAN 



35 



TAN 



with clay roundabout the tank, the necessity for the use 

 of Roman cement is avoided. 



In the forty-ninth volume of the 'Transactions' of the 

 Society of Arts Cpart ii., p. 12'i, is a communication from 

 Mrs. Davies Gilbert respecting a cheap method of con- 

 structing tanks for receiving water from the roofs of cot- 

 tages, which has been successfully practised at Eastbourn, 

 in Sussex. A reservoir having been dug seven feet deep 

 and about the same wide, the bottom was covered with 

 flints laid in liquid mortar composed of one measure of 

 grey chalk lime (made of chalk marlj well beaten up with 

 three measures of clean sea-sand. The side walls were 

 built of the same materials, leaving a small space at the 

 back of the wall, which space was filled up with the same 

 sort of grout or liquid mortar. The tank was then roofed 

 over with a dome, formed, without any centering, of 

 smaller flints well bedded in mortar. A hole was left in 

 the centre, and covered with a hood, within which was 

 hung a pulley with a rope and bucket for drawing water 

 from the tank. This account was published in 1833, and 

 in 1H37 an article appeared in the ' Labourers' friend 

 Magazine,' in which it i's stated that such tanks had been 

 found very useful during three dry summers. One, less 

 than seven feet deep and wide, had supplied two labourers' 

 families during that time, while most of the springs in the 

 neighbourhood were dry. This paper describes a brick 

 tank with sloping sides, the diameter at the base being 

 smaller than at the top, and with a dome-shaped top 

 formed by making each row of bricks project one-third 

 d that immediately below it, and balancing the 

 it by filling up the back with earth as the work pro- 

 . One of the flint tanks, constructed as above de- 

 scribed, nt the Kastbourn workhouse, is twenty-three feet 

 deep and eleven feet wide. Only ninety bushels of lime 

 were allowed for its construction, including two coats of 

 plaster, and the work was executed at ten shillings per 

 hundred square feet. 



In the article last quoted from, it is observed that a 

 currunt of air has been supposed to promote the purity of 

 the water presened in tanks. If so, it may be easily pro- 

 vided for. Where the pre\ ailing winds do not blow soot 

 and leaves upon the roof, the water is found to remain 

 good, even for drinking, without clearing out the rubbish 

 more than once a y 



In addition to tanks for water, every farm-yard should 

 have one to collect the liquid portion of tne manure, 

 which is washed by the rain through the refuse litter, and 

 also the urine of the stalled cuttle. Though not yet gene- 

 rally adopted in England, in France. Germany, and espe- 

 cially in Belgium, such tanks are considered as necessary 

 to a farm as any of its most common buildings. They are 

 usually constructed of an oblong shape, of brick well 

 ited, with one or more divisions, and capable of con- 

 taining at lea^ ten times as many hogsheads as there are 

 heads of cattle on the farm. They are vaulted over, 

 having a small aperture, in which a p'ump is placed, suffi- 

 cient to allow a man occasionally to clear out the sedi- 

 ment, when the liquid has been pumped up. The best 

 shape to contain a large quantity in the smallest space 

 would be like (host- before described; but they cannot 

 niently be made sufficiently large, and a cubical to: in. 

 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 3 cubes of 15 feet, 

 or a cavity capable of containing upwards of !(),()() cubic 

 feet of liquid. In this tank the urine is diluted with water 

 to prevent too rapid decomposition, and also to retain 

 the ammonia which is formed ; for which purpose gypsum 

 and sulphate of copper are sometimes put into the tanks. 



It' the soil be not sandy, clay will answer in-trad of mor- 

 tar to connect the brickwork, and a plastering of lime r 

 cement will be Miffieient to ke-p out the worms: but in 

 ils the bottom and sides must, be puddled, 

 p in the liquid ; and it. may be advantageous to 

 h.uld tin- walls in cement, altogether. The liquid from 

 'aWes is carried into (lie tank by a main 

 nieted of brick or stone, and which receives a 

 ier of smaller drains from every part of the yards 

 'attV-xhi-d-. Thus the litter in" the yard is always 

 dry, and none of the richness of the manure is lost by 

 ion. 



'c is vaulted like a cellar under the 

 Mouse and stables, which are Washed out twice every 



day, and all the dung and water are swept into a cess-pool 

 communicating with the tank. Thus a very diluted, but 

 rich liquid soon fills the first 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 fermentation, by winch 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 properly diluted, it accele- 

 rates vegetation in a surprising degree ; but if put on 

 fresh, it burns the grass or any vegetable it touches, be- 

 cause the ammonia is in a caustic state. If a cow drop 

 her urine in a field in a hot summer's day, all the grass it 

 has touched becomes yellow and is burned 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 ammonia- 

 cal gas-water in a tank, and, by the addition of sulphuric 

 acid in very small quantities, they may produce a very 

 fertilising liquid, which will stimulate vegetation, and be 

 a very good manure. 



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 (here 

 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 liquids by 

 merely mixing them up with water in a tank, and allow- 

 ing a certain 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 diffused, so as to be more equally spread 

 over the land. If it be true that the ammonia found in 

 some plants is chiefly derived from the very small portion 

 discovered in rain water, it follows that a scarcely percep 

 tible impregnation with this salt may have most powerful 

 (.Beets on vegetation. 



Wl:cn a farm-yard is situated on a hill, and there are 

 fields cr pastures on a lower level, at no great distance 

 from it, trie liquid from the tank may be conducted by 

 channels lined with clay, having small sluices to direct 

 the streams to any particular field. It may thus be made 

 to irrigate temporarily a considerable surface, which it will 

 greatly enrich. It may be led into the common furrow?, 

 between the lands or stitches in ploughed land, and allowed 

 to soak in them, and then it can be spread with the earth 

 of the furrow, by means of broad shovels, over the growing 

 crops, and will greatly invigorate them. This species of 

 irrigation is common in Lombardy, where much ingenuity 

 is shown in the manner in which water is made to flow in 

 small rivulets between the rows of growing vegetables. 

 The water here is supplied by streams, but the same method 

 would distribute the tank-liquor with great effect. A very 

 small quantity of this liquor, allowed to flow into the main 

 feeder of a water-meadow, will soon prove how great effects 

 are produced by impregnations which are scarcely percep- 

 lible iiy chemical analysis. 



Small as the experience has hitherto been in tills coun- 

 try of the advantages of liquid-manure tanks, it has suffi- 

 ciently proved their use to induce every man who con- 

 ! a farm-yard and erects buildings to take in the 

 tank as an essential part of his plan; and even if it only 

 collected the refuse fluids which are allowed to nan off in 

 common sewers from most houses, it would soon repay the 

 co-t i if its construction, while it rendered the ditches in the 

 neighbourhood less .subject to noxious emanations from 

 irrupted matte;- which now flows into them. Tlje 

 :e, of air into or out of a manure-tank, and the cou- 

 nt, exhalation of noxious vapours, may be prevented 

 by the use of air-traps, similar in principle to those de- 

 scribed under SKWKRS, vol. xxi., p. 310, at the points 

 where the drains enter it. 



The use of metallic cisterns or tanks, in lieu of wooden 

 casks, for containing a supply of fresh water for long 



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