This is for those who wonder just how far on the Earth's surface
a degree, minute, or second of latitude or longitude cover.

I have calculated the following table using a QBASIC program I devised
based on the formulae found in chapter 10 (The Earth's Globe) of the
excellent book ASTRONOMICAL ALGORITHMS by Jean Meeus.

km = kilometers
m = meters
mi = miles
ft = feet

PLEASE NOTE THAT ALL VALUES ARE ROUNDED TO THE NEAREST .01 UNIT.

             AT THE EQUATOR

One degree of latitude =  110.57 km or  68.71 mi
One minute of latitude =    1.84 km or   1.15 mi
One second of latitude =   30.72 m  or 100.77 ft

One degree of longitude = 111.32 km or  69.17 mi
One minute of longitude =   1.86 km or   1.15 mi
One second of longitude =  30.92 m  or 101.45 ft

  AT LATITUDE 10 DEGREES (NORTH OR SOUTH)

One degree of latitude =  110.61 km or  68.73 mi
One minute of latitude =    1.84 km or   1.15 mi
One second of latitude =   30.72 m  or 100.80 ft

One degree of longitude = 109.64 km or  68.13 mi
One minute of longitude =   1.83 km or   1.14 mi
One second of longitude =  30.46 m  or  99.92 ft

  AT LATITUDE 20 DEGREES (NORTH OR SOUTH)

One degree of latitude =  110.70 km or  68.79 mi
One minute of latitude =    1.85 km or   1.15 mi
One second of latitude =   30.75 m  or 100.89 ft

One degree of longitude = 104.65 km or  65.02 mi
One minute of longitude =   1.74 km or   1.08 mi
One second of longitude =  29.07 m  or  95.37 ft

  AT LATITUDE 30 DEGREES (NORTH OR SOUTH)

One degree of latitude =  110.85 km or  68.88 mi
One minute of latitude =    1.85 km or   1.15 mi
One second of latitude =   30.79 m  or 101.02 ft

One degree of longitude =  96.49 km or  59.95 mi
One minute of longitude =   1.61 km or   1.00 mi
One second of longitude =  26.80 m  or  87.93 ft

  AT LATITUDE 40 DEGREES (NORTH OR SOUTH)

One degree of latitude =  111.03 km or  68.99 mi
One minute of latitude =    1.85 km or   1.15 mi
One second of latitude =   30.84 m  or 101.19 ft

One degree of longitude =  85.39 km or  53.06 mi
One minute of longitude =   1.42 km or    .88 mi
One second of longitude =  23.72 m  or  77.82 ft

  AT LATITUDE 50 DEGREES (NORTH OR SOUTH)

One degree of latitude =  111.23 km or  69.11 mi
One minute of latitude =    1.85 km or   1.15 mi
One second of latitude =   30.90 m  or 101.37 ft

One degree of longitude =  71.70 km or  44.55 mi
One minute of longitude =   1.19 km or    .74 mi
One second of longitude =  19.92 m  or  65.34 ft

  AT LATITUDE 60 DEGREES (NORTH OR SOUTH)

One degree of latitude =  111.41 km or  69.23 mi
One minute of latitude =    1.86 km or   1.15 mi
One second of latitude =   30.95 m  or 101.54 ft

One degree of longitude =  55.80 km or  34.67 mi
One minute of longitude =    .93 km or    .58 mi
One second of longitude =  15.50 m  or  50.85 ft

  AT LATITUDE 70 DEGREES (NORTH OR SOUTH)

One degree of latitude =  111.56 km or  69.32 mi
One minute of latitude =    1.86 km or   1.16 mi
One second of latitude =   30.99 m  or 101.67 ft

One degree of longitude =  38.19 km or  23.73 mi
One minute of longitude =    .64 km or    .40 mi
One second of longitude =  10.61 m  or  34.80 ft

  AT LATITUDE 80 DEGREES (NORTH OR SOUTH)

One degree of latitude =  111.66 km or  69.38 mi
One minute of latitude =    1.86 km or   1.16 mi
One second of latitude =   31.02 m  or 101.76 ft

One degree of longitude =  19.39 km or  12.05 mi
One minute of longitude =    .32 km or    .20 mi
One second of longitude =   5.39 m  or  17.67 ft

              AT THE POLES

One degree of latitude =  111.69 km or  69.40 mi
One minute of latitude =    1.86 km or  1.16 mi
One second of latitude =   31.03 m  or  101.79 ft