Dear Terry, Unfortunately, I have lost your last posting, but, from memory you wrote:
** begin memory the NATO unit of angle is the 'mil' and this is useful because 1 mil ~ 1 metre at 1 km 6400 mil = 2000pi mrad = 360 deg ** end memory When I calculated 2000 x pi, I got 6238.185, and although this is approximately equal to 6400 mil, it is not sufficiently precise for it to be used as the basis of a measuring system. At best it is an approximation or a reasonably good 'rule of thumb'. I favor the idea of renaming the right angle as the 'quad' (with milliquads, microquads etc.) as the basis for the best choice for practical angle measurements in SI. If you would like me to elaborate on this let me know and I will send you a short essay on the quad. As a matter of interest, an angle of 1 milliquad would subtend a distance of 785 millimetres at a distance of 1 kilometre. Cheers, Pat Naughtin LCAMS Geelong, Australia Pat Naughtin is the editor of the free online newsletter, 'Metrication matters'. You can subscribe by sending an email containing the words subscribe Metrication matters to [EMAIL PROTECTED] --
