C ^So J 
into it, wliicli hinders the force of the wihdV 
ought therefore to have a piece of the fineft wire^^ 
to clear it with when required : And, in order to- 
have, this wire the better at hand,-it may be faften- 
ed round the Blow-pipe, in fuch a manner as is- 
reprefented in fig. i. c is the wire, faftened round 
the Blov/-pipe at d. and afterwards drav/n through;; 
a fmall hole at e-, made in the ring /. to keep it 
more fteady. 
SECT. X. 
The Blow-pipe is compounded of two parts^'- 
Tab. I. fig. 2. and 3 ; and this for the facility both 
of making, carrying it along, and cleaning it ow 
the infide when it is wanted. 
In order to determine the moft convenient pro- 
portions of this inftrument, feveral Blow-pipes of 
different fizes, both bigger and fmallcr, have been^ 
tried : The former have required too much wind^> 
and the latter being, too foon filled with the wind,- 
have returned it back again upon the lungs : 
Both thefe circumftances hindered greatly the ex- 
periments, and are perhaps even prejudicial to the' 
health. This fize, fig.’ i, is found to anfwer beh ; 
and though the hole mull be as fmall as before men- 
tioned (Se6t. ix.) yet the Tides of the pipe at the 
point mu ft not be thinner, nor the point narrower 
than here reprefented, elfe it will be too v/eak^, 
and will not give To good a flame. It is alfo to be 
obferved, that the canal throughout the pipe, but 
particularly the hole at the fmall end, muft be^ 
made very fmooth, fo that there are no inequalities, 
in it • the wind would elfe be divided, and confe- 
quently the flame made double. That Blow-pipe 
is to be reckoned the beft, through which can be 
formed the longeft and moft pointed flame from off a. 
common- 
