A desire to be useful, induces me to make the present Communication, consisting of hints extracted from recent European publications, which are worthy perusing—

Sam Bentham, Esqr. recd lately a Gold medal, for discovering the following method of preserving water sweet in Long Voyages it was bestowed by the Socy. for the encouragemt. of Arts &c—It is detailed in their Transactions. 1801—also in Tillochs Journal Vol. 12th. page 12.—He made Cases or Tanks of strong wood & lined them with Tinned Copper sheets manufactured by Chas. Wyat bridge Street London—the water having no contact with the wood—The shape of the Cases was adopted to the hold of the ship, some made to fit close under the platform, by which means, the quantity of water stowed, in the same space, was considerably greater than could have stowed, in the same space by means of Casks—He provided them for 2. Vessels say 40 Tons to each in 16 Tanks, & 30 Tons stowed in Usual manner—The water was used as wanted, but always kept in reserve, whilst the other water was good—In some of the Tanks the water had remained 3½ Years, from which 25 Galls were sent to the Society & found as sweet, as when first put in—It was taken from a Tank holding 700 Gs. & accompanied by the proper Certificates—

A work has lately been published in France by—Barry,1 giving an acct. of the method invented by Smith, of sweetening foul water by an easy process—the experiments made at Brest under direction of the ministry of the Marine, & proved very satisfactory—Smith has obtained a patent in France—the principle is as follows, the mechanical execution I am ignorant of, but our Minister at Paris could very readily obtain information or a Model if necessary—

	Blanket Doubled
	haircloth Doubled strong board full of holes well supported

The water is put in at Top. The Blanket (or Sponge) takes off the gross particles of Dirt & can be cleaned as often as required—The sand takes off some of the Dirt & the charcoal destroys all the bad smell, & the most nauseous & filthy water becomes immediately fit for use. The holes underneath the board & round the Cask, is to admit Atmospheric air into the water, to give it liveliness, the water is drawn off at A.—

At Fort Miflin the following method I was told is in use—

A large box, of which one part (which is to receive the water) is higher than the rest, no 1, 2, 3, 4 are four compartments filled with gravel or sand, growing finer as the numbers progress until it comes out at A perfectly clear—Water rising upwards, filters better; Even here the Blanket would be of use, to keep the sand longer clean—The Charcoal alone can destroy the fœtid smell & is a Russian discovery—for family use some plan like Mr Peales exhibition would answer

The Water is placed in the Top & rises thro’ the sponge like a syphon over the Outside, runs thro’ the sand then thro’ the Charcoal, & is fit for use—Smith places his apparatus in an urn like a Tea Urn, & upon very moderate terms—The french Navy has adopted the principle, after a Variety of Experiments—An Idea prevailed at first that salt water could be made fresh, but it appeared to be illusory on further experiment—Distillation appears to be the only process to obtain this end—

Bosquet2—has enrolled a Patent in England for preserving Vessels from Decay, nuisance & leakage—by filling the void spaces between the Planks, lining & timbers, with melted pitch, temper’d with Tar to be more tenacious & mixed with Cork shavings, Charcoal Dust, Ox hair &c rendering the Composition firm, adhesive, & almost everlasting, where the timbers are at a distance from each other, pieces of Cork wood or strips of Boards &c may be introduced to fill up in part & save the Composition—Ships of War in England supposed to last, 12 to 13 years, Patentee supposes after 20 ys. with his application, the Vessel would be better than at 12. ys. with only usual precautions.—Inside of the vessel now most perishable, then most lasting, rats banished, rot prevented; acts as so much ballast, is lighter however than water—£400 @ 500£ stg. would fortify (by his method) a first rate India Man—p. 249 the above taken from Monthly Magazine—April 1802. In same Number page. 213. An acct. of the Use of Mirrors in Lighthouses by E. Walker, who refers to another paper by himself in the Magazine of Decr. 1801 & also to another signed Nauticus. in Feby. 1802. Mirrors have been much used in France, from whence no doubt information could be procured.—Those in England commencd 1777. some acct. is given in Hutchinsons practical Seamanship—Concaves of Copper silverd3 disapproved of—Walker invented a Concave composite glass Mirror 18 Inches in diameter, which would appear larger than a star of the first Magnitude at 14 miles with a lamp of 10 single threads of fine Cotton several lighthouses erected on his principle which gave Satisfaction on acct. of their goodness & œconomy—Our Minister at London, could procure every necessary information, & models if requisite—The Brethren at the Trinity house would willingly give information & none more able as the light houses are generally under their direction—Walker lives at Lynn Regis—I had not the book in my possession long enough or I would have copied the whole article—

A society for promoting Naval Architecture, exists in England, 2. Vol. of their Transactions have appear’d, the 3d is in the press—They have also published experiments to ascertain resistance of different shaped bodies immersd 6 feet below the surface of water, going at the rate of 1 to 8 miles—published by J Sewell Cornhill—I some time since sent one part, relative to preservation of ship timber—another part contains an acct. of the effect of oil in preserving timber for vessels or in Bridges. The Work contains many Useful hints—

A Mr Millington of Barbadoes, now of London has found out a Method of preserving Potatoes several years for long Voyages—Vide Young’s Annals Vol. 34 page 511—He peels the Potatos & rasps or grinds them (an apple grinder would I suppose Answer), he then puts the Mash into strong cloths & presses out the Juice (a Cyder press would answer) the Cake (which should be about the size of a Cream cheese) should then be thoroughly dried, & will keep for 3 or four years, the bulk is reduced ⅚ & the weight ½—when dressed by steam or water it resumes its original bulk nearly & are like mashed potatoes—The liquor which comes from it, being mixed with an equal quantity of water, & sufferd to remain an hour or two, gives a Sediment, which makes fine Pastry or fine Starch, & possibly might pay for the Manufactory. Experiments might immediately be made—Potatoes injured by Frost, if thus treated, become eatable—Care should be taken to leave, no dirt or decayed parts in the Potatoes.—With a sufficient provision of this article, & of portable soups made from coarse pieces, & bones broken up upon Rumfords principles, the health of our sailors might be much preserved.

The diffusion of Useful knowledge has of late been much increased, by a few periodical publications, the possession of which as to the past, & the early obtaining the future continuation is of great importance, & cannot be too strongly recommended—Viz.

Nicholson’s Journal—4th series, this now continued in a new series 8vo.

Tillochs Philos: Magazine 8vo. 11 Vols are published

Repertory of arts—Twelve or 13 Vol. 8vo are published—a new series is commencing

All these publications are monthly—& contain a general acct. of the progress of science, & of the new discoveries; similar publications, amongst which the Annales de Chimie, are making in France—

The Reviews, would be useful, as giving an acct. of almost all new publications—The Monthly Review perhaps the best—of Magazines—The Monthly—is the best calculated to give information of what is useful in the progressive developements of useful knowledge—I have taken the liberty of adressing the above to you, that if you judge the hints or information of sufficient importance, you will put them in a proper channel to made use of—

The Kentucky head bone arrived this day, Mr Peale is making a sketch to send to you—It does not appear to belong to the Mammoth—

I remain with the greatest respect, Dear sir Your obt Serv