888 Lord mahon’s Method of 
but it is con fider ably cheaper, and even much better, in 
all thefe cafes, to make ufe of hay inftead of hair , in order 
• to prevent the plafler-work from cracking. The hay 
ought to be chopped to about three inches in length, but 
no fhorter. 
One meafure of common rough /and, two meafures of 
flacked lime , and three meafures (but not lefs) of chopped 
hay , will prove, in general, a very good proportion, when 
fufficiently beat up together in the manner of common 
mortar. The hay muft be well dragged in this kind of 
rough plafter, and well intermixed with it; but the hay 
ought never to be put in, till the two other ingredients 
are well beat up together with water. 
This rough plafter ought never to be made thin for 
any of the work mentioned in this paper. The ftiffer it 
is the better, provided it be not too dry to be fpread pro- 
perly upon the laths. 
If the flooring boards are required to be laid very 
foon, a fourth or a fifth part of quick <a) lime in powder, 
veryw r ell mixed with this rough plafter juft before it is 
ufed, will caufe it to dry very faft. 
(a) I have practiced this method in an extenftve work with great advantage. 
In three weeks this rough plafter grows perfe&ly dry . The rough plafter, fo 
made, may be applied at all times of the year with the greateft fuccefs. The 
eafteft method, by much, of reducing the quick lime to powder is, by dropping 
a /mail quantity of water on the lime-ftone, a little w' ile before the powder is 
intended to be ufed : the lime will ftill retain a very fufikient degree of heat. 
§ 10 . 
