3 1 8 Mr, mudge on the Conjlruflion 
Firft, then, the tool itfelf ufed by them for polifh- 
,ing the metal, is formed with infinite difficulty. The 
firft defcribed polifher is directed to be made by covering 
the tool with farcenet, which is to be faturated with a 
folution of pitch in fpirit of wine, by fucceffive applica- 
tions of it with a brufh, till it is covered* and by the eva- 
poration of the fpirit of wine filled with this extrad of 
pitch; the furface is then to be worked down and finifhed 
'With the bruifer. This is all very eafy in imagination ; 
but whoever has ufed this method (which I have myfelf 
tunfuccefsfully feveral times) muft have found it attended 
with infinite labour, and at laft the bufinefs done in a 
•very unfatisfiadory manner; for the pitch by this procefs 
■will be deprived of an effential part of its compofition. 
The fpirit of wine diffolves none but the refinous parts 
of its fubftance, which is hard and untradable ; and if 
you ufe foap or fpirit of wine to foften or diffolve it, it 
will equally affed the whole furface, the lower as well as 
higher parts of it. And fuppofe that with infinite labour 
with the bruifer, it is at laft reduced to a fine uniform 
furface, it is neverthelefs too hard ever to give a good 
polifh with that luftre which is always feen in Mr. 
short’s, and indeed all other good metals. Nor will it 
give a good fpherical figure; for a perfed fphere is 
formed, as X obferved before, by that intimate accommo- 
dation 
