  McCrea’s remarks were among the most perceptive and favorable (Kermack and McCrea 1933). While he thought that Milne’s operationalist criticisms of curved and expanding space were of little import, McCrea was the first to notice the parsimony and elegance of Milne’s strictly kinematic solution to the problem of the origin of the universe’s expansion. Since a search for such a solution had vexed relativistic cosmology for several years (McVittie 1931), McCrea suggested that Milne’s mechanism should be immdiately shown to be part of relativistic cosmology (Kermack and McCrea 1933 p. 529).