NavList:

I have a question regarding lunar distances and more specifically about the methods for calculating the local mean time.  As far as I know there were several methods used in the old days. My own solution is divided into two sub-calculations (of which you can use one or both):

1. Mean time = ( RA+LHA – sideral time at mean mid day), the expression within brackets is in sideral time and has to be converted from sideral time to mean time.

2. Mean time = mean time at the sideral mid day + (RA+LHA), the expression within brackets to be converted to mean time.

Both methods are described in three of my textbooks from 1845, 1873 and 1896. It seems to me that the first method – according to my textbooks - was more commonly used than the second one.  My question is if anyone knows when (which year) these two methods were introduced.  I guess that the second method was introduced later than the first one.

Kent N