$08 Composition for Weath er -boar ding . 
nature of the stone employed, which is procured from 
Verona. 
Chauvron, the first who set up a chemical printing 
office at Paris, after having traced the design on stone 
with a resinous ink, merely wets it with water, and 
wipes off the water from the design. Printing ink is 
then applied by beating in the common way with balls ; 
and, as this does not adhere to the wet stone, the resinous 
strokes only produce an impression. Chauvron is said 
to have printed a great deal of music in this way. 
We must observe, that, where nitric acid is not used, 
the prints will never he so fine, and so many impressions 
cannot be taken off. The use of nitric acid therefore 
cannot be too strongly recommended. 
NO. 
Account of a Composition for preserving Weather 
boarding , 8£c. By William Pattexsox, Esquire 
I HAVE often thought something much wanted for 
preserving weather-boarding, &c. from the injuries of the 
weather. Tar and oker, and other mixtures recommend- 
ed for the purpose, I have tried, but do not find they an- 
swer. I therefore made many experiments to discover a 
composition better adapted to the purpose, and think I 
have found one which answers my expectation : it is im- 
penetrable to water, is not injured by the action of the 
weather, or heat of the sun, which hardens it, and conse- 
quently increases its durability; it is much cheaper than 
paint, and more lasting. 
* Repertory of Arts, vol. 8, p. 126, From the Transaction 6 of the Society for 
the Encouragement nf Arts ^ 
