Toward the end of February, when construction work was beginning to come to an end, Mawson decided it was time for reflection and some necessary formalities. On the morning of 25 February he brought the men together under a flagpole to claim possession of the lands around Commonwealth Bay in the name of King George V.

Archie McLean called it ‘the day of days in so far as the history of our stay in this place is concerned’:

At 10.30am we had a church service conducted by Dr Mawson. Following this the Union Jack was run up to our flagpole after a short speech by Dr Mawson explaining the nature of exploration done in the past in the vicinity … As if to show how magnificent it could be the wind blew strong from the hills with driving snow … We gave [the flag] three cheers and hearty ones they were.

With these necessary preliminaries out of the way, the real business of scientific discovery could now get under way.