NavList:

I think electronics has opened up better and cheaper solutions than contemplated by Vannevar Bush.  Here is a project in the field of robotics from a few years back that addresses a similar problem of maintaining vertical orientation: http://www.dprg.org/projects/2003-01a/ . A Google search for “integrated circuit accelerometer” turns up a large number interesting and relatively inexpensive devices. Similarly, there are compasses, etc. In fact, I believe a whole Sextant might be automated and probably the military has done so.

BTW, thanks for the friendly advice a few weeks back on choosing a sextant. I decided that I would get both a bubble sextant and a marine one. I got an A-12 on eBay and it looks virtually unused. To get it in operation I have two major tasks: 1) replacing the Xylene in the bubble chambers (the A-12 comes with a spare) and 2) removing the Aluminum battery holder for the bubble illumination light. With #1 I have ordered a set of Bristol wrenches and am buying a syringe. Is there anything else I should be on the lookout for? #2 is my more serious concern. I can pull the tube out about an inch or so, but no further. There are slits in the walls of the tube and I can see light from the slit on the opposite side. This means that I’m fortunate that there is no battery in the tube with the resultant corrosion. Do any of you have any special tricks for removing the tube? Heat/cold, etc.? I know that plumbers have a special wrench used on Chrome-plated bathroom pipes and I am thinking of getting one of those. Perhaps, if I could rotate the tube sufficiently I might wear down the point of contact and binding. (This type of wrench has a lever arm with a self-tightening belt that is put around the pipe.)  

Thanks,

Peter Hollings

>I also like making things, and making them well. A usable gyro, mechanic or

>otherwise, would exceed my capabilities by far, a bubble spirit - even a

>DoubbleBubble - would not. And I would be thrilled if I could build a bubble

>spirit that is significantly more stable than the ones known sofar -- no

>matter the practical use.

>As far as practical navigation: gyros have such superior properties which

>never could be matched by any bubble spirit. They can seek North for once, a

>spirit level never could.

>Do I sense, though, that you have come to agree with the concepts of Bush's

>idea?

>I'd be delighted.

>H