Marcus Berger wrote in USMA 21717:
>Yes, but aside from this simplicity one must mention that it would just be
>a matter of choosing an average diameter that would yield exactly that
>value. I don't know if the actual value is technically tied to the
>official "sea level" on our planet (what I mean is we all know that this
>value, 40 Mm, is not exact). Perhaps someone here could clarify this to
>us. If this is not the case what would stop us from *defining* that
>specific diameter so that this issue can be definitively settled?
J. F. Hayford reported to the International Geodetic and Geophysical Union
in 1926 that;
Equatorial circumference of the earth = 40 076.594 km,
Polar circumference of the earth = 39 941.028 km.
My source does not state whether these figures are for sea level, as seems
likely, or if they take account of land and mountains. However, the
uncertainty in the radius of the earth can not exceed 50 metres. That is,
the uncertainty is only one part in 100 000.
Joseph B.Reid
17 Glebe Road West
Toronto M5P 1C8 Tel. 416 486-6071
