According to Wharton, "A Log is the official document in which the progress of the ship from hour to hour is recorded, with such official notes as the alteration in sail carried, expenditure of provisions and stores, etc. A Journal contains this information in a condensed form, with such observations as the officer keeping it may feel inclined to insert." However, as Beaglehole notes, "the border-line between the two is far from strongly marked."
Upon examination of the above sources, an interesting pattern emerged. It appears that all forms of the Endeavour journal (i.e., Canberra, Admiralty, Mitchell) carry the incorrect latitude, and all existing forms of the Endeavour log (i.e., Greenwich, Official Log, Palliser Hudson) carry the correct value (with a slight variation of a single minute of latitude).
Such a finding corroborates pre-vious investigations into the order in which the original holographic copies of the Endeavour journals were made and suggests that Cook himself might have made the latitude mistake.
Apparently the first journal copy made was the hybrid Greenwich Manuscript, wherein the latitude in question was recorded correctly, albeit in log form. Thus, because the log portion of the Greenwich Manuscript was copied from Cook's Holographic Log, one could conclude that the missing portion of Cook's original contained the correct latitude.
The next journal copy to be made was the Mitchell Manuscript, which, according to Beaglehole, has the appearance of the work "of a rather careless and lazy transcriber," and contains numerous places where Cook had to insert words omitted by Cook's clerk, Richard Orton. Otherwise, it was a copy of Cook's holographic journal (or drafts thereof), and as such carried forward the miscopied latitude.
The Mitchell Manuscript and the Canberra Manuscript were prepared in approximately the same timeframe and it is difficult at times to determine which was written first. Beaglehole cites content differences that indicate that the Canberra Manuscript followed the Mitchell Manuscript, which would indicate that it could not have been the source of Orton's work in the Mitchell Manuscript. Therefore, when preparing the Mitchell Manuscript, Orton must have been copying from some other form of Cook's prior work and the only other known sources appear to be Cook's Holographic Log and his holographic journal drafts, of which only a few fragmentary sections survive. Given that Cook's Holographic Log apparently carried the correct entry, as evidenced by its accurate transcription into the Palliser Hudson Copy, the Mitchell Manuscript with its incorrect entry must have been copied from Cook's fragmentary journal drafts.
It would follow that Cook too would have worked from his prior drafts when preparing what became the more polished Canberra Manuscript. Therefore, if both Orton and Cook used the preliminary journal drafts as the source of their work and both incorporated the same incorrect latitude entry, it seems to follow that the source itself was incorrect. As Cook was the author of the drafts, it would appear that Cook himself miscopied the latitude from his Holographic Log.
When the final Admiralty Manuscript was prepared, it was copied in large part from the Canberra Manuscript, although it also shares certain similarities with the Mitchell Manuscript. Like its two sources, however, the Admiralty Manuscript perpetuated the latitude error.
The "latitude discrepancy" also underscores the legitimacy of those changes that were not carried into the second edition. The fact that the Hawkesworth Copy is the only identified source of the accurate information other than original log entries (including those in the Greenwich Manuscript) suggests that the "unexpected" corrections are both authoritative and correct. It is unlikely that the longitude, latitude and editorial changes would have been made within the print shop, where no original sources would have been available.
Why those changes were overlooked in the hastily prepared second edition remains a mystery.