No. 7. 



Concrete for Cisterna. 



205 



po;e, which ;vill be tlie fir?t fow days of tliaw- 

 ing weather, I cover it well with wheat straw, 

 pay two or three feet tliick, and as it bej^ins 

 to separate from tlie wall I push the straw 

 down as far as it can be got, and occasionally 

 do this during- the summer. My ice-house 

 frequently has snow in it when the season 

 comes round for filling it. 



Robert H. Archer. 

 Churchville, Hartford co., IMarylaml. 



For the Farmers' Cabinet. 



Concrete for Cisterns. 



If you do it, let it lie done iccll, and not " uell enough." 



Concrete is a compound of lime, clean sand 

 and pebbles, or coarse gravel, or stone broken 

 small; these materials in proper proportions 

 well mixed, it is ascertained when they be 

 come dry form a wall, or foundation of great 

 strength and stability, which is impervious to 

 water. In England a sea wall of a thousand 

 feet in length, and of great height, has been 

 constructed of these materials; it has also 

 been used both there and in Franco for vari- 

 ous purposes connected with civil engineer- 

 ing with great effect. 



An cnirineer of eminence in his profession, 

 has just furnished me with the proportions of 

 the ingredients, and stated the manner in 

 which the concrete is used, viz: 



One bushel of pulverized stone lime, not 

 slaked. 



Two bushels of rZeorr sand. 



Four bushels of small stones, to be clean, 

 and none larger than a hen's egsr. 



All must be we/l mixed together dry, then 

 wetted a little .so as to be like mortar, turned 

 over a few times with a shovel, and immediate- 

 ly thrown from a height of eight or ten feet in- 

 to the place where wanted, and not disturbed 

 afterwards. It sets very quickly, and water 

 must be kept from it until it has set. 



No more of this mixture should be wetted 

 at a time than is intended for immediate use, 

 otherwise it will wholly or partially set be- 

 fore it is deposited in its place of destination, 

 and will be rendered comparatively of little 

 value. 



These ingredients when mixed for use, lose 

 near one-fifth of their previous bulk or mea- 

 E'jre ; it is therefore important to ascertain 

 the capacity of the space intended to be 

 filled by the concrete, and in procuring the 

 materials of which it is composed, to ob- 

 tain ofle-fi.lh more of the lime, sand and stone, 

 or pebbles, than that capacity, otherwise the 

 work will have to be suspended till more ma- 

 terials are obtained to finish it. 



The ingredients entering into such a per- 

 fectly close union as to fill all the interstices, 

 is the cause of the diminished bulk of the 

 combined materials. 



It is believed that concrete of the composi- 

 tion stated, would be the best adapted of any 

 other material for the piirpose of constructing 

 rain water cisterns, furnishing a permanent 

 security against leakage at a very reasonable 

 expense. 



To make a cistern of ten feet in diameter, 

 and twelve feet deep in the clear, which 

 would hold between five and six thousand 

 gallons ; dig out twelve feet in diameter and 

 thirteen feet deep; have prepared a circular 

 case of rough boards properly braced, ten feet 

 in diameter and twelve feet high, which place 

 in the excavation, so as to leave r;n equal 

 space all round it, and support it one foot 

 Irom the bottom. First throw in the concrete 

 to fill the bottom evenly one foot in depth ; 

 then commence throwing in round the out- 

 side of the ca^e till the space is completely 

 filled up solid to the top. It should be per- 

 mitted to remain in this slate for two or three 

 weeks to dry and liarden, when the case 

 should be taken to pieces, and removed. 

 Tiiere will remain a beautiful cistern more 

 completely compact and free from cracks or 

 flaws than can be made by walling with 

 bricks or stone. It will not Le necessary to 

 plaster it; but if plastering should be applied 

 it ought to be put on thin and even ; no gocd 

 ever comes of putting a thick coat on a cis- 

 tern, the great object being to make a coat 

 free from cracks, which is most effectually 

 accomplished by having it made thin, light, 

 and even on the surface. A thick coat con- 

 tracting more than a thin one in drying and 

 leaving cracks. 



To make a cistern of the size above stated 

 with concrete, it is believed, from calculations 

 carefully made and allowing for shrinkage 

 by combining the ingredients, that it would 

 require 72 bushels of good stone lime, 144 

 bushels of clean sand, and 288 busheLs of 

 very coarse clean gravel, pebbles, or brokp^i 

 stone. These when combined and used as 

 indicated, will make a solid rock cistern that 

 will hold v.-ater as long as rocks liet. 



Lapis. ' 



Sweet Potutoe. 



The sweet potatoe is somewhat dilTicult to 

 preserve for seed. In several attempts to 

 keep them through the winter we almost 

 totally failed. Recollecting to have some- 

 where read ths.t smoke was a great preserva- 

 tive of the sweet potatoe, we last fall pncked 

 in very dry earth a box of them, and placed 

 it in a position free from frost, and exposed to 

 the influence of smoke. The result was en- 

 tire success. A few large ones, whicii we 

 intended to have used, were laid on top, and 

 covered with a mat: they were forgotten, and 

 remained there till May, perfectly sound. 



