One of the earliest observations in Australia was by the Victorian observer Francis Abbott in 1862, who pointed out possible changes in both the stellar positions and some of the star colours within the cluster. Innes noted this again in 1906. Strong debate on the subject started in 1908, likely initiated by James Nangle, who in 1927 was to eventually become Sydney Observatory's Government Astronomer. Discussions feature in the J. BAA., 18, 384 (1908), and the debate continued in J. BAA, 19 and by R. A. Proctor in 1915 in J. BAA., 27, 29 and 30. Each debated such changes on the grounds of detecting "alleged" true stellar motions within the cluster - a sure indication of distance. Photography sufficiently improved evidence for proper motions in the mid-1920's, and the production of the first suitable plates in various colours featuring NGC 4755 stars. Between 1900 and 1920, other than several observational descriptions of this object, like that of Sydney amateur Walter Gale, data from this era now can only be considered as general information.
“Southern Astronomical Delights” © Andrew James (2002) Sydney, Australia