ART OF BUILDING. 249 



to. Where it is intended to construct a house of stone 

 and then cover it with cement, the face of the walls 

 should be left as rough as possible ; therefore, small 

 stones will answer better than large ones ; the joints on 

 the outside should be left as open as possible, and no small 

 stones or mortar should be put in between them. After the 

 walls are completed the cement may then be applied. 



The cement or mortar should be made of pure lime, 

 and if it is slacked with water in which lime has been 

 dissolved, so much the better ; the sand should be pure 

 and coarse, from the size of a pea to the head of a large 

 pin, and mixed with a suitable quantity of lime and hair. 

 This mortar should be put on, and floated over all at one 

 operation, and should be done as quick as possible. 



Only one coat should be applied, as another would not 

 stick, if applied, the first frost would take it off. The 

 plaster may afterwards be beautified by a lime wash 

 made of milk instead of water, of any required color ; 

 the cheesy part of the milk forms with the lime a kind 

 of varnish without gloss, which is not acted upon by wa- 

 ter and air. 



A cement put on as here directed '^permanent and 

 will stand fifteen or twenty years without repair. 



Stone houses are not only the most durable when prop- 

 erly built, but do not yield in beauty to those of any other 

 material, and where stones are plenty, they are the most 

 economical. Stone or brick houses should never be 

 plastered upon the stone, but upon lathes fixed to fur- 

 rings, (see article, plastering). 



Chimneys. The building of chimneys has always been 

 considered a very important part of the mason's trade. 

 There are a few principles which we conceive may be of 

 advantage to the practical man in this part of building. 

 Count Rumford, whose experiments on the economy of 

 fuel and heat are numerous and interesting, says, that 

 the back of the chimney should never exceed two thirds 

 of the opening in front, and that the jambs or sides 

 should incline to the back in an angle of 135 degrees, or 

 what is the same thing, three mitres : because this fare 

 or opening, sends out more heat than any other ; which 

 may be easily explained by those who understand the 



VOL, i. NO. x. 22* 



