Gn the Effects of Mildew on Canvas. SIS 
6f the value of the canvas. If we add to this the inconvenience, 
the delay, the insecurity, to which the rotting, or even the 
weakening of a ship’s canvas may give rise, and reflect that the 
safety of the vessel may be put in jeopardy, and that her total 
loss is sometimes occasioned by such a cause, we shall be still 
more impressed w ith the necessity of encouraging every attempt 
to And out a remedy for so formidable an evil. 
Tent-canvas, from its exposure to damp in coming in contact 
with the ground in any situation, but especially in moist and 
sultry climates, gets mildewed, and rots in a very few weeks. 
This occasions a heavy loss, and subjects the Army to much in- 
convenience, from the difficulty in many cases of procuring new 
supplies. 
Were the whole canvas, therefore, that is required by the 
army and navy, cured by an antiseptic preparation, the con- 
sumption would be reduced fully one-fourth at least in timl of 
peace;' and in time of war, the saving would be more than 
doubled. The advantages arising from a diminution in the 
quantity used must be obvious, especially in the event of a war 
breaking out with the powers in the North, from whence the 
greater part of the raw material comes, from which canvas is 
manufactured. 
The prospect of a war with the Northern Powers would raise 
the price of hemp and flax to double or triple of what it is in 
ordinary cases during peace ; but were the whole, or even half 
the canvas used by Government and the ship-owners of Britain, 
prepared in an effectual manner, the lessened consumption would 
act as an antidote against inordinate prices, and render the 
country in a much less degree dependent on foreign supplies. 
According to tables made out for the use of the Navy Board 
in May 1821, by Messrs Dempster, it was shewn that the sav- 
ing to the nation in using their twine-canvas, in preference to the 
contract kind in general use, would be as 16 to 27 J, and would 
save L. 150,000 annually in time of war. But, without enter- 
ing into such extensive calculations, in place of much less than 
one- third, as there stated, it may confidently be assumed, that 
about one-fourth of the whole value of the canvas used annually 
in the Navy is lost from the baneful effects of mildew ; — not that 
this quantity is rendered totally unserviceable, but the fabric of 
