December 6, 2005
Whatever Floats Your Boat Posted by Frederic D. Schwarz at 10:55 AM EST The other day, while looking through the 1842 edition of John F. Watson’s Annals of Philadelphia and Pennsylvania, I came upon the following: “About sixty-five years ago [i.e. around 1777, when you’d think Philadelphians would have had other things to worry about], many hundred persons went out to the Schuylkill to see a man cross that river in a boat carried in his pocket! He went over safe, near High street. B. Chew, Esq., saw it, and told me of it, and my father saw the same at Amboy. It was made of leather—was like parchment—was about five feet long—was upheld by air-vessels, which were inflated, and seemed to occupy the usual place of gunwales. For want of a patent office, the art is probably lost. The fact gives a hint for light portable boats for arctic explorers, and suggests a means of making more buoyant vessels on canals.” I was amazed to read this. Way back in Revolutionary days, long before rubber became a common industrial material, someone had built a working inflatable boat! But in fact the technology is much, much older. According to this article: http://www.allinflatables.com/support/articles/inflatable-kayaks-01.html “the history of the inflatable boat goes back as far as 880 B.C, when the Assyrian king Ashurnasirpal II ordered troops to cross a river using greased animal skins, which they inflated continuously to keep the vessels afloat. In ancient China, during the Sung and Ming dynasties, inflated, airtight skins were used for crossing rivers.” I’ll bet that even the “airtight” Chinese skins were at least a little leaky, as well as the ones used to cross the Schuylkill. Still, Watson’s suggestions about possible uses for this technology proved quite prescient, as both were patented by other inventors before the end of the decade. On his 1845 Arctic expedition, Sir John Franklin brought along an inflatable boat made of rubberized cloth that had been designed by Lt. Peter Alexander Halkett: http://www.nmm.ac.uk/server/show/conWebDoc.9470 And Watson’s idea about canal boats was turned into an invention by none other than Abraham Lincoln, who received U.S. patent No. 6,469 for a scheme to use inflatable chambers to lift boats over sandbars (which, fortunately for posterity, did not turn out to be practical enough for Lincoln to make a business of it): Click here to see the patent office record.
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