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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Artificial horizon
From: Bruce Stark
Date: 2005 Feb 20, 18:23 EST
From: Bruce Stark
Date: 2005 Feb 20, 18:23 EST
Alex,
I have a six inch #98 Starrett machinist's level. Cost about $70 as I recall. In the box it says "A bubble movement of 1 division (1/10") on main vial indicates an elevation of .005" per foot." (Those " marks indicate inches, of course, not seconds of arc.) I find it easy to read the bubble to a fifth of one of the divisions. You can probably do better.
Trouble is, once you get the mirror leveled it tends to drift off slightly from effects like the sun warming the base, movement around the base, etc.
As for the reflecting surface, I found a piece of high quality mirror quite satisfactory.
Bruce
I have a six inch #98 Starrett machinist's level. Cost about $70 as I recall. In the box it says "A bubble movement of 1 division (1/10") on main vial indicates an elevation of .005" per foot." (Those " marks indicate inches, of course, not seconds of arc.) I find it easy to read the bubble to a fifth of one of the divisions. You can probably do better.
Trouble is, once you get the mirror leveled it tends to drift off slightly from effects like the sun warming the base, movement around the base, etc.
As for the reflecting surface, I found a piece of high quality mirror quite satisfactory.
Bruce
