1. Phys. Rev. Lett.,6, 147 (1961). This paper, hereafter referred to as (I), deals with a point mass source for the Schwarzschild field.Suppl. Nuovo Cimento,20, 1 (1961), hereafter referred to as (II). A third paper (III) (submitted for publication) will deal with the Poincaré compensating stresses for the classical point electron. A brief description is given inBull. Am. Phys. Soc.,7, 31 (1962).
2. See the discussion in Einstein’s essay:Notes on the Origin of the General Theory of Relativity inEssays in Science (New York, 1953), p. 78, § 7.
3. A. Einstein:Ann. Phys.,49, 769 (1916).
4. See the arguments byW. Lenz, as described inA. Sommerfeld:Lectures on Theoretical Physics, vol.3 (New York, 1952).
5. However a discontinuity ing 11,r will produce a discontinuity in the radial acceleration as described by (2.9). Note that some authors impose as one of the requirements for « admissible co-ordinates » thatg μν be of classC 1; seee.g.,J. L. Synge:Relativity, The General Theory (Amsterdam, 1960), pp. 1, 268, 273;A. Lichnerowicz:Théories Relativistes de la Gravitation et de l’Electromagnetisme (Paris, 1955), p. 5;W. Israel:Proc. Roy. Soc., A248, 404 (1958).