We shall criticize him only in a particular case, e.g., when he defined the velocity of light by where is the
vacuum velocity of light and the time-time component of the metric. In second approximation, the velocity of light then
is shown to obey a Poisson equation. Cf. [653*], Section 4. Apparently, he did not know about early papers by Einstein,
Nordström [457], and Ishiwara [306, 307].