1—In a preceding paper a relativistic formulation of the law of gravitation was obtained, in the flat private space of any fundamental observer in the substratum or smoothed-out universe, in terms of
r
-measures. In other papers, general formulae have been given for the transformation of forces, equations of motion, etc., from
t
- measures to
r
-measures. They may be at once applied to express the law of gravitation in
r
-measures, in the public hyperbolic space
de
2
in which the extra-galactic nebular nuclei appear at rest. The present paper carries out this programme, and so obtains the law of gravitation in the form appropriate to the
r
-dynamics, which corresponds to classical mechanics. 2—Let
O
be any fundamental particle of the substratum, P the position vector of any other particle
P
with respect to
O
, at epoch
t
, in
t
-measure. The
t
-clocks of the fundamental observers have been graduated so that the fundamental particles appear in uniform (Whitrow 1935) relative motion.
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