Next message: George Huxtable: "Re: Halley's lunars, back in 1698-1700"
On May 7, 2004, at 10:54 AM, Robert Eno wrote:
> So let me get this straight:
>
> 1. Any index error in the sextant will be reflected by one reading
> differing from the other; that is the upper limb observation may be
> greater than it should be, while conversely, the lower limb observation
> would be less than it should be. They should balance each other out.
>
> 2. The sum total of the off and on readings divided by four should
> yield
> the correct semi-diameter. There is no need to factor in the index
> correction because one value should balance out the other. In
> otherwords,
> the index correction is already inherently factored in by virtue of the
> upper and lower limb values differing by X minutes of arc.
>
> Am I on track here gentlemen?
>
>
> Robert
>
yes
