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resources in the rest of the world. The petroleum resources of this country have been developed and depletea in a ratio far beyond that of other countries, so that although we are producing to-day two- thirds of the world's production, the opportunities elsewhere for increasing production are much greater than in the United States. Geologists and those well-informed on foreign resources believe that in all probability the world contains enormous reserves of oil that can be obtained upon demand. Although to obtain oil from these reserves may not be as satisfactory as to obtain it within the confines of the United States, the outlook tends to assure the future of the internal combustion engine.

" Fortunately oil may be obtained from other sources than oil fields. In various parts of the United States, particularly in Col- orado, Wyoming and Utah, are enormous bodies of oil shales from which oil may be obtained by destructive distillation, as benzol is obtained from coal. The United States Geological Survey has esti- mated the quantity of oil locked up in the richer shales of the three States mentioned as perhaps ten times the amount of the oil reserve in the oil fields. In Scotland the retorting of oil from oil shales has been on a commercial basis for more than 50 years, and antedates the oil industry in the United States. Commercial and semi-com- mercial experiments are being made in order to determine whether the oil shales of the Western States can be mined and retorted prof- itably in competition with petroleum from oil fields. This problem has not yet been solved, but these shales constitute a latent reserve that protects the future needs of the country for motor fuel as far as these needs can be foreseen. However, oil cannot be obtained from the shales on a large scale without heavy investments and the development of the industry must be spread over many years. Also, when the time comes, the consumer will probably have to pay more for his gasoline."

The oil shales not only of the United States, but of the whole world, await development as a source of oil fuel. The commer- cial possibilities of this development depend almost entirely on the relative cost of production and the selling price of natural oil and shale oil. In comparing the cost of production of natural oil from wells and of oil produced by distillation from shale, long experience has shown that in any field which is considered worthy of commercial development the cost of the oil at the wells should not exceed one penny per gallon, or 255. per ton. In favourable cases it is only a fraction of this amount. In the shale field the shale has to be mined and transported to the retorts in which it is distilled, and the earthy residue, which amounts to from 15 to 17 cwt. for each ton distilled, has to be handled and disposed of. Labour and fuel have to be supplied - for the retorting process and the retorts have to be kept in repair. With selected shales a yield of 30 to 40 gal. of crude oil per ton of shale may be obtained. The mining and retorting costs will amount to at least los. per ton, without capital and general charges, or 3d. per gallon for the crude oil as compared with the above figure of one penny per gallon at the wells. It is clear that the initial cost of crude oil obtained from shale puts it quite out of court in competition with natural oil,' except in situations so far from oil wells that the extra cost is compensated for by that of transport of natural oil. It is clear that, in times of plenty, the natural oil can, if necessary, be sold at a price of one penny per gallon, which will at least pay the cost of pro- duction; the shale oil works on the other hand would have to sell at a loss, or to shut down and disband the large staff of skilled workers required for the prosecution of the industry.

The history of the oil industry during the period 1870-1920 shows a succession of waves of over-production and low selling prices, as new oil fields have been developed. The effect of these periods of plenty and of low prices has on the whole been to develop consumption of oil as a fuel; but their effect on the shale industry of Scotland has been to make the profitable running of the industry so speculative that it has never been possible to develop it on a really large scale, though ample supplies of shale are known to exist there. With natural oil, cost of production per se has very little to do with the fixing of the selling price, but with shale oil cost of production is the vital consideration. The best hope for the development of the shale-oil resources of the world appears to depend n a continuance of the interest recently shown in the United States in this question as being of vital importance to the industrial welfare of that country. Great natural resources in oil shales have been proved to exist; it only remains to develop systems of mining and retorting on the best modern lines, by which shale oil can be placed on the market at a minimum cost.

Though in the opinion of experts in Great Britain this can never approach the actual cost of production of natural oils in existing fields, shale is thereby not necessarily excluded as one of the more important sources of oil fuel. First cost is only one among the conditions which will determine this development.

The production of oil by the carbonization of bituminous coal is also receiving much attention in the United States, as well as in Great Britain and Germany. This problem involves economic questions which do not arise in connexion with oil shales. Chief among these is the fact that, while in the distillation of shale about > 7o% of the shale distilled is a valueless earthy residue, 60 to 70% of the bituminous coal is retained after carbonization as a smokeless fuel of a higher value for domestic purposes than the original coal.

Peat. The scarcity of fuel in the United Kingdom during the World War led to considerable pressure upon the British Govern- ment for the establishment of a serious inquiry into the possible development of peat. The matter was considered by the Ad- visory Council of the Department of Scientific and Industrial Research, resulting in the institution of the Fuel Research Board, by whom an Irish Peat Inquiry Committee was appointed. The history of this inquiry has been dealt with in the published reports of the Fuel Research Board. 1 As the subject was recog- nized as one of world-wide importance, Prof. Pierce Purcell was appointed Peat Investigation Officer to the Fuel Research Board in 1919, and through him close touch was maintained with the principal peat developments in Europe and America. In the summer of 1920 Prof. Purcell visited Canada and the United States, and investigated the work of the Peat Committee of the Canadian Government at the Alfred Bog, near Ottawa. In the following summer he visited some of the more important peat stations in Germany, Denmark and Sweden.

In Germany the Wiesmoor peat station has been in operation since 1910. The peat is dredged, macerated and spread on the surface of the bog to dry. By stacking under cover, the moisture of the peat blocks can be reduced to 25% solely by air-drying. For steam-raising purposes two tons of air-dried peat are equal to about one ton of coal. At Wiesmoor eight water-tube boilers are fired with peat. The average fuel consumption is stated to be from 2-7 to 3 kilos of partially dried peat sods per kilowatt hour, and the cost of the peat is taken at five marks per ton. A scheme was stated to be on foot for the establishment of a line of peat generating stations from Konigsberg on the east to Wiesmoor. The promoters of this scheme appear. to have ignored the fundamental difficulty which applies to the winning of peat in quantities sufficient to meet the day-by-day requirements of any large central station. When it is realized that the peat deposit in a good bog 20 ft. deep is only the equivalent of a 12 or i4-in. seam of coal, it will be evident that even an output of 1,000 tons a day of air-dried peat involves the laying out and develop- ment of an enormous surface. At the Zehlonbruck station, near Konigsberg, it was proposed to use 920,000 tons per annum, or about 2,500 tons per day. Prof. Purcell states that to win mechan- ically 900,000 tons of air-dried peat in one season at least 4,500 men, women and children would be required, and the area over which the spreading and drying operations would extend could not be less than 9,000 ac., or say 15 sq. miles. He suggests that, in dealing with any production over 60,000 to 80,000 tons per annum from any single district, the difficulty would increase as the square of the production; and he considers that it is only by the development of these smaller units that progress will be made. There was evidence in 1921 that a steady development on these lines was in progress in Germany.

In Canada and in Ireland the application to local conditions of mechanical cutting or dredging, maceration, air-drying and harvesting has been studied with encouraging results. In the summer of 1920 peat was cut, macerated, spread on the bog at Turraun in Ireland, air-dried and harvested there, and a hundred tons of this air-dried peat were sent to H.M. Fuel Research

1 Reports of the Fuel Research Board for the years 1918-9, and on the winning, preparation and use of peat in Ireland; reports and documents.