On painting Linen Cloth in Oil Colours . 95 
colour, in value to government nine pounds six shillings ; 
the expense of the process not exceeding six shillings. 
This I effected by calcination, raking aside the ashes 
and sprinkling them with water, to prevent loss of paint 
through excess of heat. By passing the calcined matter 
through a fine sieve, it is perfectly prepared for grinding ; 
it grinds well, possesses a good body for covering with, 
and dries well with a good gloss. Its increase of bulk, 
in comparison with common colour of equal weight, gives 
it the advantage of covering more work. The colours 
yielded by the calcination of different coloured canvass 
are as follow : viz. Canvass which has been painted with 
black paint only, produces a black colour. Canvass fi- 
nished black, but which has had a previous red or yellow 
ground, will produce a dark chocolate colour. Canvass 
painted lead colour will yield a good dark lead colour. I 
am, &c. 
W illi am Anderson. 
Fort sea, March 25, 1807* 
To C. Taylor, M. D. Sec. 
Certificates, dated March, 1807, were received from 
the following persons, viz. 
A. Stow, lieutenant and commander of the gun-brig 
Steady, stating, that in the preceding month of October 
he had received on board his ship a set of hammock cloths, 
painted after the method invented by Mr. William An- 
derson, which had been constantly in use since the time 
above mentioned, and appeared fully to answer the end 
proposed, of rendering the canvass soft and pliable, of 
preventing its cracking, or the paint peeling off, and 
which in the old method had been a subject of much com 
plaint. 
John Pridy, lieutenant and commander of the Gladia 
tor, and formerly commander of the Dapper, on which 
