Only one aeroplane could be taken by the expedition and this necessarily had to be a single-engined machine, as there were no twin-engined aeroplanes at the price which the expedition could afford to pay. As a result great care had to be taken to choose a machine which was equally good as a seaplane and as a skiplane, with quickly interchangeable undercarriages, and which would combine as many of the most essential qualities as possible. The first essential was wooden construction. Many people, apparently qualified to give an opinion, will say that wooden construction is not suitable for service in cold climates, but I have found it extremely good during eighteen months' hard service in Greenland, and again after two and a half years in the Antarctic in much more severe conditions. The chief advantage on an expedition is the ease with which even major repairs can be carried out. It is not necessary to take a comprehensive supply of airframe spares as these can all be cut straight from a length of suitable timber, and even main and tail plane ribs can be constructed with a little patience. The wooden construction appears to be every bit as robust as metal and, of course, cannot corrode.