The resistance to motion round a curve has not been so systematically studied that any definite rule can be formulated applicable to all classes of rolling stock and all radii of curves.
The law, e.g., of the equality of the radii of a circle cannot be exhibited to sense, even if equal radii may be so exhibited.
The medusa has a pronounced radial symmetry, and the positions of the primary tentacles, usually four in number, mark out the so-called radii, alternating with which are four interradii.
In diameter, sometimes surmounted by trees in the midst of a treeless plain and sometimes arranged in circles and on radii, and decreasing in size with distance from the centre of the field - has been variously explained.
The radii, thicknesses, refractive indices and distances between the lenses, was solved by L.