Having the shape of a curve everywhere equidistant from a fixed point
Assuming that the molecules are spherical, R.
His last publication, which appeared in 1878, was on spherical harmonics (Beitreige zur Theorie der Kugelf unctionen) .
The problem then resolves itself in the solution of a spherical triangle.
For safety during hibernation and moulting, book-scorpions spin a small spherical cocoon.
In the case of more considerable distances, however, a globe of suitable size should be consulted, or - and this seems preferable - they should be calculated by the rules of spherical trigonometry.