425 
Rope Making, 
In the course of experiments made for the discovery 
of a varnish proper to defend his new lanthorns from mois - 
ture, Citizen Rochon did not employ resins or copal, 
which are always somewhat friable, but a perfect solu« 
tion of elastic gum in drying linseed oil. This varnish 
or imguent having fixed the attention of Genouin, that 
learned chemist demanded whether it might not be prac 
ticablfc to use it in making bougies and other medical in* 
strumeiTts, which were also at that time very much want- 
ed. From this suggestion, Rochon employed the Eng- 
lish machine for weaving whips to make the more con- 
sistent part of the instrument. He plunged this woven 
piece in a mixture of melted wax with a little ochre, then 
drew it through a wire plate to take off the superfluous 
wax, and render it perfectly smooth ; after which he ap- 
plied the varnish of elastic gum, which completed the 
instrument. 
Sartori, ornamental painter at Brest, pointed out to our 
operator that fish glue is preferable to parchment size upon 
open wire cloth, because it is more transparent and stronger 
ROPE MAKING. 
Mr, John Curfs ( Sheffield ), Patent^ for laying a Rope ^ 
or twisting and forming the Strands together that compose 
the round Rope,-~^^^ Presuming (says Mr. Curr) that 
there is in use a wheel, or engine, for twisting the strands 
at the top end of the ropery, and another moveable one 
towards the bottom end of the ropery, and that the large 
tooth- wheel, in each of tliese wheels that drive round the 
small nut- wheels, contain ninety-four teeth each ; and 
that there are three smaller nuts working into the tooth- 
wheel of the wheel, or engine, at the top end of the rope- 
