562 PRACTICE OF AGRICULTURE. Part III. 



made ; these are small at the inside of the kiln, but are sloped wider, both at the sides 

 and tlie top, as they extend towards the outside of the building. The uses of these aper- 

 tures are for admitting the air necessary for supplying the fire, and also for permitting the 

 laborers to approach with a drag and shovel to draw out the calcined lime. From the 

 bottom of the kiln within, in some cases, a small building called a horse is raised in the 

 form of a wedge, and so constructed as to accelerate the operation of drawing out the 

 burned limestone, by forcing it to fall into the apertures which have been mentioned 

 above. In other kilns of this kind, in place of this building there is an iron gate near 

 the bottom, which comes close to the inside wall, except at the apertures where the lime 

 is drawn out. When the kiln is to be filled, a parcel of furze or faggots is laid at the 

 bottom, over this a layer of coals, then a layer of limestone (which is previously broken 

 into pieces, about the size of a man's fist), and so on alternately, ending with a layer of 

 coals, which is sometimes, though seldom, covered with sods or turf, in order to keep 

 the heat as intense as possible. The fire is then lighted in the apertures ; and when the 

 limestone towards the bottom is completely calcined, the fuel being considerably ex- 

 hausted, the limestone at the top subsides. The laborers then put in an addition of 

 limestone and coal at the top, and draw out at bottom as much as they find thoroughly 

 burned; and thus go on, till any quantity required be calcined. When limestone is 

 burned with coals, from two bushels and a half to three and a half, on a medium three 

 bushels of calcined limestone, are produced for every bushel of coal used. 



S588. A very complete lime-kiln on an improved plan, has been erected at Closebum 

 in Dumfrieshire, by Monteith. Instead of the wide and shallow circular kiln, these 

 kilns are elliptical and deep. Some parts are added to it which are found of most im- 

 portant use. The first is a kind of roof or cover. The disadvantage of the want of some 

 contrivance to protect kilns in stormy weather, has been long felt, and many attempts 

 have been made to apply some kind of cover, but, we believe, none with such success as 

 that used at Closeburn. The next addition is having cast-iron doors below, at the 

 opening where the kiln is drawn. There is a grating, through which the ashes fall 

 while drawing the kiln, which makes that operation a much less disagreeable employment 

 than formerly ; and the ashes and small lime thus separated are excellent for agricultural 

 purposes. There is often a great loss of fuel, from allowing lime-kilns to cool when 

 there is no demand ; all that is necessary to be done, is, to shut the cast-iron doors, above 

 as well as below, and the dampers in the chimneys. The heat is thus preserved, and 

 fuel saved, by keeping the kiln hot, to be ready for use as soon as wanted. {^Farm. Mag, 

 vol. xvi. p. 134.) 



3589. Booker's lime-kiln is of an oval form, twenty -two feet high, two feet wide at 

 the bottom, nine feet in middle, and gradually contracted to three feet at top. It is 

 lined with brick, and, instead of being covered with a dome, Booker adopts a cover of 

 cast-iron with a vent in it, which cover is placed on a ring of three feet diameter, built 

 into, and fixed on the top of the kiln. The cover, by moving on a pivot, is easily 

 thrown oflP when the kiln is to be charged, and being put on during the process of cal- 

 cination, it both increases the draught of air through the kiln, and by acting as a rever- 

 beratory furnace, is attended with a considerable saving of fuel. (Dumfries Beport, 

 p. 594.) 



3590. Burning lime in heaps. Where fuel is abundant, lime may be burned in heaps 

 as in charring woods, or in clumps like bricks. The fuel is intermixed, and the 

 whole covered wjth turf or mud, in which a few holes are pierced to admit the passage of 

 the smoke. (Farm. Mag. vol. xvii. p. 61.) 



3591 . Machines for pounding li?nestone have been erected, but the eflfect of the powder 

 so obtained, both as a manure and for cement, is so much inferior to that of burnt lime, 

 that they liave long since been generally laid aside. 



3592. Salt is procured from rocks, springs, and from the sea. In Cheshire, particu- 

 larly in the neighborhood of Northwitch, the salt works are very extensive. Great quan- 

 tities are got in the solid form, but not sufficiently pure for use. In this state it is con- 

 veyed from the mines to the Cheshire side of the river, nearly opposite to Liverpool. 

 It is at this place dissolved in the sea water, from which it is afterwards separated by 

 evaporation and crystallization, by a process which we shall describe. There are also in 

 the same district salt works, at which the salt called Cheshire salt is extracted from 

 brine. These works are described very intelligibly by Dr. Holland, in The Beport of 

 Agriculture for the County of Cheshire. Considerable salt works are carried on in Scot- 

 land, and in the northern counties of England on the sea-coast, by the evaporation of sea 

 ivater. At Lymington, in Hampshire, the sea water is evaporated to one-sixth of the 

 whole by the action of the sun and air. The works in which the sea water is heightened 

 into brine are called sun-works," or out-works. These are constructed on a flat down 

 or oozy beach, within a mole, which is raised, if necessary, to keep out the sea ; there is 

 a large reservoir, or feeding pond, communicating with the sea by a sluice, and adjoin- 

 ing to this reservoir a long trench, parallel to which there are several square ponds, called 



