@james-vianna The documentation of the 39th parallel and photograph of the instruments used clearly describe and show 3 microscopes. and that Direc...

@not-my-real-name I believe the scope is lifted out of the alidade. But that’s part of my question.

@bill93 Yes that had occurred to me. Even over short time of an hour there seems to be some arcseconds of oscillation

@leegreen hour angle method. Altitude method is not worth anything.

I have created an excel spreadsheet to reduce the observations. And loaded a year of ephemeris data. It’s a complicated thorough computation. But test...

I’ve done a lot zenith angle elevation in the Hagerstown MD valley to radio towers. So the vertical angles are somewhat large 1-3°. So not skimming. ...

@field-dog Thanks. The formulae in those are useful. And fits.

@field-dog?ÿ Itƒ??s a power supply, D batteries, but not necessarily for the reticule. There is a lamp to illuminate the horizontal circle. And a sec...

@field-dog my favorite. 1955 and a newer T3 isnƒ??t better?ÿ

@field-dog?ÿ I live for T3 angles, with a 60 count micrometer. 8 to 12 sets. Yeahƒ?? you donƒ??t pick up before those numbers crunched. And thatƒ??s...

@field-dog?ÿ Unfortunately the new guy usually canƒ??t deal with an 8 lb windmill swing. Slows the whole process down. So the PC on hammer and new gu...

@field-dog?ÿI had an apprentice on the crew and he was working an assignment of practice questions. He was totally confused. While driving to office I...

@olemanriver?ÿBeware: There are more than one emulator! You want i41CX+ by Antonio Lagata.