The reason why the "Aube" sailed ahead of the "Comte de Paris" was to "gain time for fear the British might get the start of them". Yet the New Zealand Company's survey ship "Tory" had sailed from Plymouth on 12 May 1839, before Langlois and his associates had made their first approach to the French government, and as early as June the British Government was considering sending Captain William Hobson to act as Lieutenant-Governor over such parts of New Zealand as might be acquired from the Māori. Hobson was notified of his appointment in August. He arrived at the Bay of Islands on 29 January 1840, and on 6 February the first signatures were placed on the Treaty of Waitangi. At that date, neither of the French ships had left France. While they were still on the high seas, in May 1840 Hobson proclaimed British sovereignty over the South Island by virtue of Captain Cook's discovery. The same month HMS "Herald" arrived at Akaroa, bringing Major Thomas Bunbury, who was carrying a copy of the Treaty of Waitangi for signature by the southern chiefs. At Akaroa it was signed by two chiefs, Iwikau and Tikao. Three weeks later at Cloudy Bay, Bunbury made a declaration of British sovereignty over the whole of the South Island, based upon the cession by the chiefs as signatories to the Treaty of Waitangi. It was not until 19 August that the French colonists were landed at Akaroa.