I wish we had known about this when we were finding our way across the blue Pacific with a plastic sextant and a Seiko self winding watch!
at the end of the seventeenth century, even as members of learned societies debated the means to a longitude solution, countless cranks and opportunists published pamphlets to promulgate their own hare-brained schemes for finding longitude at sea.
surely the most colorful of the offbeat approaches was the wounded dog theory, put forth in 1687. it was predicated on a quack cure called powder of sympathy. this miraculous powder, discovered in southern france by the dashing sir kenelm digby, could purportedly heal at a distance. all one had to do to unleash its magic was to apply it to an article from the ailing person. a bit of bandage from a wound, for example, when sprinkled with powder of sympathy, would hasten the closing of that wound. unfortunately, the cure was not painless, and sir kenelm was rumored to have made his patients jump by powdering—for medicinal purposes—the knives that had cut them, or by dipping thier dressings into a solution of the powder.
the daft idea to apply digby’s powder to the longitude problem follows naturally enough to the prepared mind: send aboard a wounded dog as a ship sets sail. leave ashore a trusted individual to dip the dog’s bandage into the sympathy solution every day at noon. the dog would perforce yelp in reaction, and thereby provide the captain a time cue. the dog’s cry would mean, “the sun is upon the meridian in london.” the captain could then compare that hour to the local time on ship and figure the longitude accordingly. one had to hope, of course, that the powder really held the power to be felt many thousand leagues over the sea, and yet—this is very important—fail to heal the telltale wound over the course of several months. (some historians suggest that the dog might have had to be injured more than once on a major voyage.)
http://littlepotato.tumblr.com/post/158212426/scientific-subterfuge-powder-of-sympathy
