of Metals for reflecting Aelef copes. 3 1 1 
The beft kind of handle for the metal is made of lead, 
a little more than double its thicknefs, and fomewhat 
lefs in diameter, of about three pounds weight, with a 
hole in the middle (for reafons to be fliewn hereafter) a 
little larger than that in the metal : this handle fhould be 
cemented on with pitch. The upper edge of this weight 
mull be rounded off, that the fingers may not be hurt;, 
and a groove, about the bignefs of the little finger, be 
turned round juft below it, for the more conveniently' 
holding and taking the metal off the tools. 
Abe manner of figuring the metal upon the bones . 
When the bruifer, brafs tool, and metal, are all 
brought to the fame figure, and have all a true good 
furface, the next part of the procefs is to give a 
correct fpherical figure and a fine face to the metal,, 
upon the hones. It will be neceffary to premife, how- 
ever, that the hones fhould be placed in a veffel of water, 
with which they fhould be quite covered for at leaft an 
hour before they are ufed, otherwife they will be per- 
petually altering their figure when the metal comes- to 
be ground upon them. The fame precaution is alfo ne- 
ceffary, if you are called off from the work while you are 
grinding r 
