
 Subj : Vacuum Sucks!                                                           

JM>I was looking for a low-tech manually operated device though...

JM> JW> A water column could make a low level one as well.

JM>By connecting a sealed column and lifting the container?

Yeah, or drop the hose. Fill the container & a long, air-tight hose with water.
Hold the container so that th water can all drain out the hose. Then, while
keeping a J-bend at the bottom (to make sure no air bubbles in) lower the hose
(over 33 feet will do) until no more water comes out the J-bend. Note that the
water in the column will tend to "bounce," so the greater the vacuum you seek,
the deeper the short side of the J-bend should be. The colder the water is, the
harder the vacuum you can create (0.03 atmospheres for room temperature, 0.007
for nearly freezing).

I suspect your garden-variety hose will leak or collapse long before you can get
it that low.

