On the lowest computation I think the number could not have been less than a hundred millions." He explained how he arrived at this estimate, the reliableness of which is beyond dispute, though it may seem incredible to those who have not been in southern seas during the season when the sooty petrels "most do congregate." Taking the stream of birds to have been fifty yards deep by three hundred in width, and calculating that it moved at the rate of thirty miles* an hour, and allowing nine cubic yards for each bird, the number would amount to 151,500,000.

The burrows required to lodge this number would be 75,750,000, and allowing a square yard to each burrow they would cover something more than 18 1/2 geographical square miles.

(* Flinders is calculating in nautical miles of 2026 2/3 yards each.) The mutton-bird, it will therefore be allowed, is the most prolific of all avian colonists.

It has also played some part in the history of human colonisation.

When, in 1790, Governor Phillip sent to Norfolk Island a company of convicts and marines, and the Sirius, the only means of carrying supplies, was wrecked, the population, 506 in all, was reduced to dire distress from want of food.