Daily Talk
The Rambam builds a table of the sun's correction accurate to the minute, and then tells you to throw away the minutes of the number you feed into it. The largest correction he ever asks you to make is one degree and fifty nine minutes, and at two points in the circle the correction is nothing at all. Why does a man this careful spend a whole chapter telling you what not to measure?
Never More Than Two Degrees
Loading...
About This Talk
Chapter 13 gives the working method for the true position of the sun: find the mean position, find the apogee, subtract one from the other to get the course, and read the resulting angle off a table of seventeen values. If the course is under 180 degrees the angle is subtracted from the mean position and if it is over 180 degrees it is added, while at an even 180 or 360 there is no angle at all and the mean position is already the true one. The Rambam then fixes the precision of the whole operation, discarding minutes under thirty in the course and rounding thirty and above up to a full degree, ignoring seconds entirely in every sighting calculation, and closes by noting that a method for locating the sun on any date is also a method for dating every equinox and solstice, past or future.