^yS CEMENTS. 



brick-dust, until, by dropping u, little upon a stone, 

 you perceive it hard enough ; then pour it into 

 water, and immediately make it up in rolls, and it 

 is tit for use. 



Another^ finer. — Take resin, one ouuce; pitch, 

 two ounces; add red ochre, finely powdered, until 

 you perceive it strong enough. Sometimes a small 

 quantity of tallow is used, according to the heat of 

 the weather, more being necessary in winter than 

 in summer. 



Either of these cements is of excellent use for 

 turners. By applying it to tlie side of a chuck, 

 and making it warm before the fire, you may fasten 

 any thin piece of w^ood, which will hold while you 

 turn it ; when you want it off again, strike it on 

 the top with your tool, and it will drop ofi' imme- 

 diately. 



A strong Cement f^r Electrical Purposes. 



Melt one pound of resin in a pot or pan, over a 

 slow fire ; add to it as much plaster of Paris, in 

 fine powder, as will make it hard enough, then add 

 a spoonful of linseed-oil, stirring it all the while, 

 and try if it be hard and tough enough for your 

 purpose ; if it is not sufficiently hard, add more 

 plaster of Paris ; and if not tough enough, a little 

 more linseed-oil. 



This is a very good cement for fixing the necks 

 of globes or cylinders of electrical machines, 

 or any thing else that requires to be strongly 

 fixed. 



Another^ softer. — Take resin, one pound; bees- 

 wax, one ounce ; add to it as much red-ochre as 

 will make it of sufficient stiffness ; pour it into 



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