The Sun.
London, England, 1822-05-29 00:00:00

IMPROVEMENT IN SAIL-CLOTH.

The peculiar notice with which our Paper has
of late been honoured by our Commercial Friends in general
s
and by the. Shipping Interest in particular, renders us anxious
not to overlook any information which may prove beneficial to
British Merchants and Ship-owners. We therefore revert with
pleasure to a subject mentioned in our Paper of the 22d. Jan.
last, the application of science to the improvement of British
SaiLcloth. Since that period, we have had ocular: inspection
of various specimens of Sails, partially or wholly prepared by
his process, and exposed to everypracticattest, together with
"unprepared canvas ; and if any'doubt had before remained on
Our nunds, it would- have -been impossible for us to resist the
conviction arising from the result..of these experiments. Not
only have pieces of prepared and of unprepared canvas been
tried separately, under circumstances exactly similar ; but, in
the same sail, alternate breadths of prepared' and unprepared
Canvas have been used—the former without receiving a speck,
and the latter being spotted all over with mildew !
When we consider how much the durability of canvas de-
pends on its being unsusceptible of mildew, and on its flexibili-
ty, both which qualities are imparted by this process, we must
regard the discovery as one which peculiarly demands the at-
tention of those persons (whether public bodies or individuals)
to whose care the directitm of our shipping is entrusted. Two
points appear to have been established by incontestible proof—
Ist, that sails made of prepared canvas are one-fifth cheaper
than the bleached kinds ; and, 2dly, that they will last twice as
long. It has been calculated, that at the present prices of coker
and prepared improved Scotch canvas,thesa'ving on a complete'
et of sails would be as follows :

s. d.
For a Merchant Ship of 400 tons 31 13 9 -
700 tons - 66 8 4
1200 tons - 95 0 11
For a Man of War of 100 guns - 15,3 7 2
• 50 guns - 105 9 3
36 guns . 107 2 7
Fora Brig of l4 guns - 25 18 9
For a Cutter of l4 guns - 48 2 9
The testimonials to the improved durability of the prepared
canvas are so many, so various, and so highly respectable, as to
form a body of proof wholly irresistible. They consist of-
1. Certificates by officers of the navy, who, by express com-
mand of the Admiralty and Navy Boards, made comparative
observations on the effect of weather, &c. on sails of prepared
and unprepared canvas, during long voyages in various climates.
2. Certificates by masters of merchant vessels.
3. Statements of the use of both kinds of canvas for tents and
awnings in hot climates, and during the rainy seasons.
4. Opinions of the Committee of British Shipowners and
other gentlemen personally conversant and interested in matters
of shipping.
5. Judginents of men of science, approving of the philoso-
phical principles of the invention.
- Of the first class are the reports made of sails used in his
Majesty's ships Ranier, Crown, Solcbay, Crocodile, Antelope,
and Chatham ; in all which instances, without exception, whilst
the unprepared canvas was, in the words of the different oflicers,
" very much mildewed, " completely mildewed," " consider-
ably worn," " rotten," and 44 fit for no other use than paper
stuff;" the prepared kind was " free from mildew," good
and serviceable," " perfectly sound," preserving its colour and
strength," and " fit for any purpose."
Similar experiments were made, with the same results, on'
board the merchant ship Fame, from London to Calcutta 4nd
back; 'Marquis of Hastings, from London,. to Bombay and
back ; Trafalgar, to and from the Coast of Africa ; brig Eden,
for several months to and at Jamaica and the Havannah; Nep-
tune, in Davis's Strait and the Greenland Fishery; Active and
Bacalhao, in the coal trade between Shields and London, &c. &c.

The third and fourth classes of testimonials most fully cor-
roborate the two preceding. The fifth class rest on the high
scientific authority of Dr. Marcet, Dr. Babington, Mr. Arthur
Aikin, and Sir Humphry Davy. Dr. Babington states, that
" so far from the substances used (in Browell's process) being
detrimental, they must, in his judgment, tend to preserve the
canvas not only from mildew, but from other causes which
might be likely to affect it." Dr. Marcet states, that from ex-
periments made with brown Scotch canvas, and with bleached
canvas furnished to Browell and Co. by order of the Navy
Board, which had been manufactured according to their in.
structions of 1814, it was found that Browell and Co.'s process
is a " remarkably powerful prevention against mildew, and
that the brown Scotch canvas was more effectually protected by
it than either of the kinds furnished from Deptford Dockyard.
Mr. Aikin (the ingenious Secretary to the Society of Arts), in
,a letter to Messrs. Browell and Co. relates the results of various
experiments made with the same kinds of canvas as were sent
to Dr; Marcet, with similar effects. Mr. Aikin is thence led to
think, that " the alkaline boiling which the Government canvas
undergoes, may so destroy or weaken the natural union between
the vegetable fibre and coloring matter, as to render it more
liable to spontaneous decomposition ; and concludes, that canvas
made as nearly as possible from the raw material, after being
submitted to Drowell and Co.'s process, would be the most dur-
able of any." • Sir Humphry Davy, after examining the experi-
ments made by the two kst mentioned Gentlemen, says, in a
letter to Dr. Babington, that ,he " considers the evidence of
those experiments as unquestionableg" Finally, among the tes-
timonials of this kind, we must not forget to rank that of Rear-
Admiral Sir Edward, Codringtoh, who, after examining the
pieces of canvas with -which Dr: Marcet had made his experi-
ments, which fully confirmed those made at sea by direction of
the Admiralty, declares " his hope that a discovery of such vital
importance may obtain the, just reward of general adoption in
hia Majesty's. Navy."