In 1931 an aerial survey of Northern Labrador was sponsored by the American Geographical Society (see Geographical Review, Jan. 1932). In the summers of 1931 and 1932 photographic flights and ground-control triangulations were made covering the Labrador Peninsula from Nachvak Fiord, north to Cape Chidley, and the shore line from Nachvak south to Port Manvers.

The use of mechanical transport, and the replacing of the old-fashioned methods of travel by plane or tractor, is a new feature of polar exploration. As will be seen in the following articles, each one by a specialist, the use of tractors is still, in most cases, at the experimental stage; but great advances have been made since Captain Scott took motor-sledges to the Antarctic in 1910.

Modern polar research calls for a much more specialised and efficient travel technique than did polar exploration of even a few years ago; and, as a result, great strides have been made in perfecting the modern mechanical methods of transport. The old method of dog-sledging, with its comparatively low speeds and light loads, is already being replaced, to some extent, by mechanically driven sledges and aeroplanes. Several expeditions at work in the Arctic and Antarctic during the last few years have been able to make excellent use of air transport, but the first mechanically driven sledges were at best only moderately successful, and each reached its limit according to its construction either as a result of bad ice, slush, or deep powder snow, where the wheels or caterpillar band became bogged.

Mechanical transport was first used by the author of this article at the time of the investigation of the Norilsk mining field (Lat. 69° 20′ N., Long. 88° 8′ E.) in 1925 for the purpose of taking goods from the port of unloading to the village of Dudinsk on the River Yenisei over a distance of 85 km. across tundra. At that time the tractor industry had only just come into being in the Soviet. Special machines for cross-country freight did not exist, so imported caterpillar tractors of the Reno make were used, drawing sledges freighted up to five tons. Certain constructional defects in the machines, and particularly in the sledges, as well as lack of experience in the work, combined to make the results far from satisfactory at this stage. At the end of the winter we had only succeeded in making one full journey and had transported only ten tons of profitable cargo on three machines. Nevertheless, this first experiment was valuable in that it demonstrated that, given mechanical improvement, the tractors might revolutionise polar transport. In this case, for instance, three machines had transported rapidly a cargo which would have required a caravan of two hundred and forty reindeer. It was ascertained also by this trial that caterpillar tractors of this type were suitable only for work in the vicinity of a base on smooth and hard roads. For transport over long distances in new and soft snow they were less satisfactory.

One of the earliest of the Hudson's Bay Company's experiments in tractor transport work was at Rupert's House in 1924. The machine used was a Citroen modelled after the tractor-type machines which had given such excellent service in the Sahara. It was not successful, however, so details covering its operation would be of little interest.