"First published in March, 1927" on copyright page of Second Edition (1929), seen on Archive.org.
At new WorldCat as of 2022-08-23, library records show (with Description abbreviated):
Author: J. W. Dunne
OCLC 470386501 (208, ill) 1170350669 (none) 8326404 (208, ill, 23cm)
Author: John William Dunne
OCLC 70320303 (2 pl, 208, diag, 23cm) 558586275 (208, 8o)
Those are the 5 records, easily found among 111 sorted by year, which report both publisher Black and year "1927" (without brackets or copyright sign; none found thus).
Library of Congress reports this edition only "from old catalog"; author credited only by full name and not as from title page.
OCLC 70320303 is the LC record, inferred.
