NavList:

Well done on getting moving so quickly Michael.  Your Moon results look very good.  You tempted me to get my MkIX2BM out tonight.  Like me, these old machines need to be exercised frequently to prevent them stiffening up.  At first, I could see nothing, but then I remembered that this MkIX has a habit of not allowing its ‘wound up shutter’ to drop down properly.  One I shoved that down, I could see both the Moon and Jupiter, but I was consistently shooting about 15’ high on both.  I was hovering around ‘five degrees increase’ territory, so maybe that had something to do with it.  I’ll try it on the Sun next chance I get and see if it’s the same with the Sun.  I’ll also get a Smith’s peri-sextant out and see how that compares.  If the error is consistent, I’ll just carry a large index error like I do with my A12.  What I have noticed with home filled sextants is that the tiltability which the bubble chamber was designed to provide is not as good as it might once have been, and you really need to keep the bubble vertically in the centre of the chamber as well as laterally.  Jupiter was getting very close to the Sun tonight, and I was hoping we might see, not the cow, but Jupiter jump over the Moon tomorrow.  I checked, but it’ll happen in daylight below the horizon where I live, so I’ll miss it.  DaveP