AMsS "Opinion as to the value of double-bodied vessels."

AUSTRONESIAN DOUBLE-BODIED BOATS AND A EARLY MENTION OF STEAMBOATS

GOWER, R[ichard] H[all], of Ipswich, in the India Service, naval architect, inventor (fl. 1767-1833). AMsS "Opinion as to the value of Double-bodied vessels," comparing the hydrodynamics of a catamaran and a proa. Bifolium on laid paper watermarked "1813. 4to, pp. 2, [2] blank, addressed on verso of blank leaf to "Miss Applegath," folded for delivery. N.p., n.d., London? 1813?].

Gower (fl. 1767-1833), was a sea captain and naval architect. If indeed this was written the year the paper is watermarked, or even close to that year, it contains a very early mention of steamboats. Glasgow engineer Henry Bell launched Britain's first truly commercial steamboat, the Comet, which was built on the River Clyde in 1811-12. Here Gower writes about Pacific Austronesian proas, which usually have two unequal-length parallel hulls. He was an inventor of several optical instruments for measuring a ship's through the water, published a pamphlet about the instruments (1792), and was the author of A Treatise on the Theory and Practice of Seamanship (1798), which long remained a standard work. Gower writes approx. 275 words about proas, which we quote in full: "By means of a double bodied vessel great stability may be affected with a small area of midship body; consequently, as a great extent of canvas may be exposed to catch the breeze on so small a body, without danger, much speed has been expected, and the flying proas of the Ladroon (i.e. Ladrone) Islands [now known as the Mariana Islands] are quoted as examples of the kind. Those however, who shall expect great speed, upon a wind, from an equally double-bodied vessel will be disappointed. The cause is obvious; for, while sailing before the wind when the course is direct and in a line with the keels of the vessel, the water will pass freely between the bodies, but when this vessel shall sail upon the wind, by which her course will be rendered oblique to the keel by the angle of leeway, the water will, in consequence, not pass freely, but hang between the bodies, and going with them, will thereby retard the velocity of the vessel. Double boats being more valuable only where the course is direct, the plan is more applicable to steam-boats than sailing vessels. A flying proa is no comparison in this case, she not being composed of two equal bodies whereby to lock up dead water between them when sailing upon the wind; but receiving her stability from a counter-balancing body to windward, which acts by its weight, and is of too little magnitude and depth beneath the surface to lock up a volume of dead water." Gower concludes by drawing a small sketch of a proa marked with an A and a B, explaining that "A being the body of a flying proa, and B the balance on the surface of the water. B is ever made the windward side by either end becoming the head when it is necessary to tack the proa. R. H. Gower." For Gower see, Taylor, Mathematical Practitoners of Hanorverian England 1714-1840, #840, and ODNB. 84681