514 



MISCELLANEOUS GARDEN STRUCTURES. 



with several holes bored in it for ventila- 

 tion; or the cover may be an iron grating, 

 horizontal and a little elevated, or conical. 

 These tanks may be constructed of vari- 

 ous dimensions ; the depth and width 

 should be nearly equal; a hole should 

 also be left for the service-pipe, or that 

 which conveys the water into the tank, 

 and also for the pipe for the pump, if the 

 water be drawn out by that means. The 

 water may be filtered previously to its en- 

 tering the tank ; the hole for the service- 

 pipe ought, therefore, to be near the top, 

 and on that side most convenient for the 

 filtering chamber : this may be about 4 

 feet in diameter, and 3 feet deep. Across 

 this, about 12 inches from the side next 

 the tank, as at b, fig. 729, a slate partition, 

 a, reaching from the top to within about 6 

 inches from the bottom, should be fixed ; 

 at the bottom of the box should be put 

 clean coarse sand or powdered charcoal, c, 

 about a foot in thickness. The pipe or 

 opening, b, from the filter to the reservoir, 

 should be of ample dimensions, and be 

 made at about 18 or 20 iDches from the 

 bottom, in the small division or space 

 behind the slate. Above this opening, 

 and in any part most convenient in the 

 large division of the filter, should be an 

 opening or drain to carry off the water 

 when the tank is full. This filter should 

 also have a cover, that it may be cleaned 

 out, and fresh sand or some other purifier 

 put in as often as may be found requisite. 

 Of course the water, as it comes from the 

 roof, is to be first conveyed into the large 

 division of the filtering chamber, on the 

 opposite side to the slate partition, and, 

 passing through the sand, it rises in the 

 small division purified, when it is fit to 

 pass into the tank by the tube b. If there 

 are two or more of these filtering cham- 

 bers, or if they are of greater depth, the 

 water may be passed through the greater 

 quantity of sand in them, and be still 

 more purified." If water be brought 

 from any other source than from the 

 roof, it must be admitted into the filter- 

 ing chambers. Both the tanks and fil- 

 tering chambers should be water-tight: 

 if constructed of brick, the inner course 

 should be laid in Roman cement, and 

 afterwards the whole of the inside covered 

 with a coat about f -inch thick, of the same 

 material. Water from drains formed in 

 the ground, for the purpose of collecting 



it for domestic purposes, may be purified 

 by passing it through a sand filter pre- 

 vious to its entering the tank. Sponge 

 and flannel may also be used as filters. 

 In constructing tanks of the above descrip- 

 tion, care must be taken to have the earth 

 closely filled in around the brickwork, 

 and to allow sufficient time for the work 

 to get properly settled previously to ad- 

 mitting any great weight of water." 



In regard to the size of tanks, more 

 especially where much depends on the 

 quantity of rain water, we may here ob- 

 serve that Waistell's calculation is to the 

 effect that 126 gallons fall annually on 

 every square yard in Britain, or 2722J 

 tons to the imperial acre. Another au- 

 thority says that, taking the annual fall 

 of rain at 31 inches, it would give 3100 

 tons per acre. To show how much we are 

 independent of wells or water companies, 

 let us take for example a cottage roof, 50 

 feet in length and 10 feet in width of slat- 

 ing on each side of the ridge, which will 

 give 1000 square feet of surface, equal to 

 WW square yards. This, taking the fall 

 of rain at Waistell's calculation of 126 

 gallons per square yard, will give us nearly 

 14,000 gallons of water per annum, all to 

 be secured by merely building a water- 

 tank, and placing shoots — or rones, as they 

 are called in Scotland — round the eaves of 

 the house ; — a precaution which, when it is 

 taken, (though this is far too seldom,) is 

 more frequently with a view to carry away 

 the water to waste in the nearest drain, 

 than to turn it to any useful account. 

 Rain water for vegetation, and for most 

 domestic purposes, is by far the most 

 valuable, and, when properly filtered, is 

 the purest of all for the use of the table. 

 This is one of the many instances where 

 man spurns the blessings his Creator has 

 amply provided for him, and put within 

 his reach, while ho will not avail himself 

 of them, but will dig wells, and bring 

 water for miles, by the force of his own 

 ingenuity. 



We have paid some attention to this 

 subject for a number of years, and in 

 various localities ; and we have, from cal- 

 culations made, arrived at the conclusion 

 that a supply of rain water falls annually 

 upon the roof of most dwellings — if we 

 exclude those of densely peopled parts of 

 towns and cities, where people live in story 

 above story— sufficient to supply the in- 



