While on the subject of oil-fields which are under the British Flag, mention must be made of Canada, whose oil industry has been developed for many years. The principal producing fields are in Ontario, and the town of Petrolia is the centre of the petroleum interests. But the wells are not of the prolific class, and almost without exception show a very poor return for operating. Many of them are sunk only to the shallow strata, and their operation would certainly be profitless were not a system employed by which quite a number of small producing wells are pumped by central power. From time to time, Canada has experienced various oil booms, one of the most recent being that which occurred in Calgary, in 1914. A well showed a small production of high-grade oils, and immediately the country for miles round became the centre of an oil fever, which gradually died down when a number of unsuccessful developments took place. To-day, the output of the Canadian fields is steadily declining, and all efforts to stimulate the production have so far failed. Even a Government bounty of 1½ cents a gallon of oil produced has failed to encourage an increase in output, and it is evident that, unless new fields are opened out, the future offers little hope. The total production of petroleum to-day by the oil-fields developed in the British Empire represents but about 2 per cent. of the world’s total petroleum output: it is therefore clear that, if we intend to secure our oil supplies in the future from territory under the British Flag, large supplementary sources of supply must be found. It is doubtful whether any additional liquid oil regions will be found to produce oil in commercial quantity, for, though several attempts have been made in various parts with this end in view, they have not achieved success, and numerous instances might be quoted where the employment of British capital in an endeavour to bring about this much desired result has met with failure. The question then arises: Is it possible to augment considerably Empire-produced oils from other means of development? In this direction, the future is full of promise, for, though Nature has not given the Empire freely of liquid oil-producing fields, there are immense areas of oil-bearing shales at home and in our Dominions overseas which can, without great difficulty, be turned into most useful account. It is well known that great deposits of retortable material exist within the Empire’s bounds, and many of these deposits are exceedingly rich. At the moment, however, scarcely any have been exploited, and none adequately developed. From time to time, many samples of oil-bearing shales from various parts of the Empire have been sent to this country for analysis, and these have usually been put through Scottish retorts with varying results.