Thanks to Dave Bell for posting his table of values.
I have several rules of thumb that may be helpful:
1 arc minute = 1/3438 radian = 0.0002909 radian (approximately 1/3600 or
even 1/3000).
Hence 1 arc minute corresponds to 1 inch at 3438 inches, or about 1 inch
at 300 feet (= 3600 inches / 12).
At a reading distance of 10 inches, 1 arc minute corresponds to about 1/360
inch, or about 0.003 inches.
1 arc second = 1/206,265 radian (approximately 1/200,000 or 5 one-millionths).
To convert from degrees to radians: multiply by pi and divide by 180.
To convert from arc minutes to radians: multiply by pi, divide by 180, and
then divide by 60.
Gordon
Gordon Uber [EMAIL PROTECTED] San Diego, California USA
Webmaster: Clocks and Time: http://www.ubr.com/clocks
