NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: About time - Antarctica
From: Gary LaPook
Date: 2012 Mar 5, 21:43 -0800
From: Gary LaPook
Date: 2012 Mar 5, 21:43 -0800
For those who have never heard of a "hydrostatic tube" it is a glass tube, closed at the top and open at the bottom, mounted vertically on the deep sea lead. The inner surface is coated with a substance that changes color when wet. As the lead is lowered the water raises in the tube, compressing the air trapped in the tube, the higher the water goes, the deeper the measurement. The trouble with this method is the rapid change in scale with depth. The water rises half way in the first 33 feet. 2/3rds at 66 feet, 3/4 at 99 feet, 4/5 at 132 feet, 5/6 at 165 feet, etc. As you can see, it is only useful in fairly shallow water. gl --- On Mon, 3/5/12, Henry Halboth <hchalboth@gmail.com> wrote:
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