3io Mr. Mudge on the Conjlruclion 
br uifers may not pafs above half an inch within the fur- 
face of the brafs tool either way, fhiftiug the bruifer 
round its axis every half dozen lirokes or thereabout. 
You muft likewife, every now and then, fhift your own 
pofition, by walking round, and working at different fides 
of the brafs tool ; at times the ftrokes fhould be carried 
round and round, but not much over the tool : in fhort, 
they muft be directed in fuch a way, and the whole 
grinding conducted in fuch a manner and with fuch 
equability, that every part of both tools may wear 
equally. This habit of grinding, as ■well as the future 
one of polifhing, will be foon acquired. When you have 
wrought in this manner about a quarter of an hour with 
the bruifer upon the tool, it will be then neceffary to 
change them, and, placing the bruifer upon its bottom, 
to work the convex tool upon that in the fame manner. 
When by working in this equable manner, alternately 
with the bruifer and tool, and occafionally adding frefh 
emery, you have nearly got out all the veftiges of the 
turning tool, and brought them both nearly to a figure, 
it will be then time to give the fame form to the metal. 
This muft be done by now and then grinding it upon 
the brafs tool with the fame kind of emery, taking care 
however, by working the two former tools frequently 
together, to keep all three exactly in the fame curve. 
The 
