400 



Burning Lime, and Limekilns. 



curb ring 



ber (Jig. 108. a) ios 

 and ash-pit (b), 

 and a cast-iron 

 cap or cover (fig. 

 107. c d), which 

 turns on a pivot, 

 and rests on a 

 fixed on the top of the ma- 

 sonry of the kiln (d). The 

 use of this cover is to pre- 

 vent the escape of more 

 heat than is necessary to 

 keep the fuel burning, for 

 which last purpose the 

 cover has only an opening 

 at top (d), twelve inches in 

 diameter. The principal 

 advantage of this construc- 

 tion is, that very little heat 

 is lost, and that lime may 

 be burned with almost as 

 ittle fuel in winter as in 

 summer; another advan- 

 tage, and one of consider- 

 able importance in a coun- 

 try sale, where a kiln is 

 not worked sometimes for 

 two or three days together, is, that by closing the orifice (d) at 

 top, and the furnace-doors (Jig. 108. ab) below, the fire may 

 be kept alive for four or five days. In the ordinary descriptions 

 of kilns without covers, the fire is usually extinguished in 

 twenty-four hours, especially in the winter season. In Booker's 

 kiln, one measure of coke will burn four measures of limestone. 

 The fuel for the limekilns at Closeburn is brought from a 

 distance of twenty-five miles, and it is found that one third of 

 the expense of carriage is saved by coking it at the coal-pits. 

 A measure of this coke burns as much lime as the same mea- 

 sure of coal ; as when coal is used in the limekiln it may be 

 said to be coked before it has much effect on the limestone. 

 One of Booker's kilns, when coke is used, yields nearly three 

 fourths of its contents of well-burned lime every day. 



The Menteath Kiln. — Where lime is to be burned with coal or 

 smoky fuel, a form has been adopted at Closeburn, which I have 

 invented, and which, from a very extensive experience, I have 

 proved to be much superior to those in common use. This 

 kiln, which may be designated the Closeburn oval limekiln, 



