be observed that here, as in the electrical and gas industries, science will no doubt continue to show us progressively ways of economising in the consumption of coal. For instance, the present average efficiency of steam raising is estimated at 65 per cent., and we are informed that there is no reason why 75 per cent. should not be attained in general practice. It may, however, safely be assumed that such economies as these are not in the long run to the detriment of the Coal Mining Industry; on the contrary they are likely to be more than off-set by the expansion of industry to which they lead.

Bunker Demand.

The quantity of coal used as bunkers by vessels engaged in the foreign trade averaged 19.6 million tons annually in the prewar period, 17.5 millions in 1924 and 16.2 millions in 1925, This serious decrease is attributable partly to the general fall in our foreign coal trade (for every million tons of coal sold abroad about 270,000 tons are needed as bunkers by the ships that convey it) and partly to the use of oil both for steam raising and for internal combustion engines.

The exact quantity of fuel oil used in the United Kingdom before the war is not known; but in 1913 it probably did not exceed 500,000 tons for all purposes. In 1924 the amount supplied to vessels engaged in the foreign trade alone was over 1,000,000 tons. We may estimate the extent of the change by comparing the gross tonnage of vessels registered at Lloyds as being fitted for burning oil, which rose from 1 millions before the war to 201 millions in 1925. Meanwhile, the corresponding figure for coalburning vessels fell from 44 to 42 millions. We may add that the tonnage of motor ships building in the world at the beginning of 1926 almost equalled that of the steam tonnage under construction.

In drawing deductions from these figures it should not be forgotten that many steamers are constructed to burn either coal or oil alternatively, and will change from one to the other according to their comparative prices from time to time.

Conclusions.

The conclusions to which the foregoing surveys lead us are as follows:

Export Trade.-(1) The depression in the British coal export trade is, in the main part of a general depression, affecting almost all European coal-producing countries: an excess of supply over demand caused partly by the impoverishment of customers, partly by the development of new coalfields, and partly by the increased use of substitutes.

(2) To a lesser extent it is due to the competition of foreign countries with us in the coal export trade, especially that of Germany.

(3) The extent to which the German export trade has been assisted by the Reparations provisions of the Treaty of Versailles is obscure, and the opinions of our witnesses differ. We can only express our conclusion that the British coal trade in general does not regard them as a serious danger.

(4) The substantial fall in British export prices during the latter part of 1925 has been followed by an appreciable recovery of the position in some, though not all, of the competitive markets; and the fall in price has been checked by a restoration of the balance between demand and supply.

Bunker Trade.-(5) In so far as the decrease in coal used as foreign bunkers is the natural consequence of the decrease in the export trade, it is obvious the quantity will automatically increase if the export trade increases. But in so far as it is due to the use of oil instead of coal, the reduction is likely to be progressive, especially if any change in the present relative positions of coal and oil as regards price takes place to the disadvantage of coal.

Home Trade.-(6) No substantial recovery in the home trade can be looked for except from a recovery of the heavy industries.

CHAPTER II.-THE NATIONAL COAL RESOURCES.

The Coal Reserves of the United Kingdom.

A Royal Commission was appointed in 1866 for the purpose of investigating, inter alia," The probable quantity of coal contained in the coalfields of the United Kingdom, and the quantity of such coal which may be reasonably expected to be available for use." It reported (in 1871) that the estimated reserves of the coal resources of the British Isles, in seams of 1 ft. in thickness and upwards, down to a depth of 4,000 ft. were 146,480 million tons; of this, 90,207 millions was the probable quantity in the ascertained coalfields, and 56,273 millions the probable quantity concealed under the newer formations, i.e., unproved coalfields. These estimates were arrived at after making generous deductions for loss in working and other contingencies, and took no account of the probable existence of coal in the South of England.

Based on the then annual production of 115 million tons, the Commission calculated that the coal resources were sufficient to last for 1,273 years.

These estimates were revised by the Royal Commission on Coal Supplies which reported in January, 1905. Accepting the same data as to possible depth of working, thickness of seams, and loss in exploitation, as those previously adopted, the second Commission arrived at the following results :

It will be seen that that Commission adopted a much more conservative view of the possible productivity of the concealed coalfields than that of its predecessor. On the other hand it felt justified, by reason partly of more accurate knowledge of the coal seams, and partly of discoveries in other directions, in basing the reserves of the proved coalfields at an estimate 10,707 million tons in excess of that of the Commission of 1871, notwithstanding the fact that upwards of 5,694 million tons had been produced in the interval.

The Commission of 1905 declined to prophesy as to the probable duration of the nation's coal reserves, having regard to the very speculative data upon which such an estimate could alone be based.

The Coal Conservation Committee, which was appointed in July, 1916, and reported in January, 1918, emphasised the importance of the economical consumption of the nation's coal "in view of the fact that the coal available in the United

Kingdom is not unlimited." The Committee, however, did not attempt to form an independent estimate of such reserves, but accepted those of the two Commissions to which reference has already been made, and of authorities on the subject whose estimates had subsequently been published

The first of these was Dr. (now Sir Aubrey) Strahan, who was a member of the Committee, and who. as Director of the Geological Survey, had issued a report on the coal resources of the world for the International Geological Congress of 1913. In that report, Dr. Strahan modified the estimates of the Royal Commission of 1905 in accordance with the new data furnished by the explorations during the interval of eight years. For example, the estimate included for the first time the newly discovered coalfield of Kent, to which Dr. Strahan ascribed reserves of 2,000 million tons; and it took into account the 20th century development of the East Midland Coalfields, the eastern extension of which justified an addition of 13,500 million tons to the reserves estimated by the Royal Commission.

Dr. Strahan summarised his figures as follows :

These figures, like the preceding ones, related to coal in seams of 1 foot in thickness or over, and lying at a depth not exceeding 4,000 ft. from the surface.

The second estimate quoted by the Committee was that of Professor H. S. Jevons, published in his work, "The British Coal Trade,” in 1915, in which he arrived at the following results :136,000 million tons. 61,000

Actual reserves
Probable and possible reserves..

The hypothesis adopted by Professor Jevons is almost identical with that of Dr. Strahan, the excess in the later estimate being accounted for largely by differing views as to the probable limits of the East Midland concealed coalfield, and of the reserves in Kent, and also by the inclusion by Professor Jevons of a purely speculative figure of 15,000 million tons as representing possible deposits of coal in totally unexplored areas.

It is noteworthy that, notwithstanding the continued exploitation of the nation's coal deposits, with one exception (and this due to the very conservative attitude adopted by the investigator as to the probable dimensions of the concealed fields), each successive estimate of the available reserves remaining is a considerable advance on its predecessor.

This is made clear in the following table :

* Excluding Ireland for the years 1922-25, both inclusive.

Recommendations resulting from previous Inquiries.
(1) Royal Commission on Coal Supplies of 1901–5.

Notwithstanding the reassuring conclusions which had been reached by the Commission of 1871 as to the potential reserves of British coal, there was a tendency on the part of scientific thinkers towards the close of the 19th century to take a pessimistic view of the extent and possible duration of the nation's mineral wealth. An opposite view was taken by men of practical mining experience, and the question was referred in 1901 to the second Royal Commission, with terms of reference wider than those of its predecessor.

The Commission sat for over three years and reported in 1905.

As we have seen, it substantially confirmed the estimates of the previous Commission, which had indicated that there was no cause for apprehension as to the exhaustion of our mineral wealth for many generations to come. The Commission arrived at a number of conclusions directed towards securing greater efficiency in the exploitation and preparation of coal for sale, its more efficient consumption, and the substitution for coal of other sources of power in appropriate circumstances. It expressed also the definite view that, owing to physical considerations, the then rate of increase in output (at that time about 4 million tons per annum) could not long continue, and added "there seems no present necessity to restrict artificially the export of coal in order to conserve it for our home supply."

The expression of this opinion inspired an immediate demand for the abolition of the coal export tax of 1s. per ton, which had been imposed in 1901, and which exporters maintained was responsible for a contraction of the foreign market. The Commission itself had accepted this contention. The tax was eventually repealed in November, 1906.