[Letters to Editor]

Abstract

I REGRET that I inadvertently wrote “sub-polar” for “sub-solar” in my remarks on Prof. G. C. Comstock's book on Sumner lines, but this lapse makes no difference really to the statement that the proper description should be zenith point, and not sub-solar point (see p. vi of preface and pp. 2, 3,, etc.). Sub-solar refers to the sun only, and does not necessarily include sub-stellar or sub-lunar, but zenith point is common to all.