I would have bet real money that this wouldn't have worked- apparently, I would have lost. Fascinating. This is the first really novel "survival" concept I've run across in some time.<br><br>I guess I'd have misgivings about versions with a wooden plunger getting wet. If the plunger swells even slightly I think it would be useless. <br><br>One question- if the fit is that tight, how do you get the piston to stay all the way down (against air pressure) for carrying?<br><br>Here's a link to some videos and a synthetic version:<br><br>http://www.geocities.com/ResearchTriangle/System/5102/<br><br>