December lo, 1914] 



NATURE 



393 



THE SUPPLY OF PIT WOOD. 



ATTENTION has already been directed in 

 Nature to the great diminution in the 

 normal supply of pitwood since the beginning- of 

 the war. This tends at the moment to raise the 

 cost of coal, and would, if continued, ultimately 

 reduce the output. The official returns ^ show a 

 great decrease in the import of pitwood from 

 foreign countries, but this need cause no alarm 

 so long as the command of the seas is retained. 

 Ample supplies are available in Canada and New- 

 foundland, and a considerable amount of home- 

 grown timber suitable for use in the mines can be 

 felled during the coming winter. 



trees in woods which are clear felled, and are sold 

 at a cheap rate, being of little value except for 

 utilisation as pit props, firewood, or pulpwood. 

 Both home-grown and foreign timber are used, but 

 the former, of which no statistics are available, 

 scarcely exceeds one-tenth of the total amount 

 consumed. In 1912, a normal year, 260,000,000 

 tons of coal were raised in the United Kingdom, 

 valued at ii8,ooo,oooL, or 95. id. per ton. During 

 the same year the imrport from abroad of pit 

 timber was 2,925,000 loads, equivalent to 

 117,000,000 cubic feet, valued at 3,660,000^. In 

 other words, to raise each ton of coal about ^ cubic 

 foot of foreign timber, costing 3^^. is required. 

 The expenditure on pit props is about 3 per cent. 







^ . v\ V 



vsv. ^ 



Fig. I.— A' Cruach before planting. Note the rocky face. From the Transactions of the Royal Scottish Arbaricultural Society. 



Timber is necessary in coal mines for support- 

 ing the roofs of galleries and main roads, for 

 sleepers on the haulage lines, etc. Steel, con- 

 crete, and masonry are used in various ways as 

 substitutes, but timber remains the cheapest and 

 most easily handled material. 



The great bulk of timber used in coal-mining 

 consists of poles 2h to 7 inches in diameter at the 

 small end, which are cut into convenient lengths 

 for use as pit props. Such poles are readily pro- 

 cured, either as thinnings or as the smaller-sized 



1 Import of pitwood fromforeign countries, 193,002 loads in September, 1914, 

 against 479,341 loads in September, 1913. The figures for the nine months 

 ending September 30, 1914, are 1,920,000 loads ; for the same period in 1913 

 as much as 2.583,459 loads 



XO. 2354, VOL. 94] 



of the price of coal. It is evident that a con- 

 siderable increase in the price of pit timber could 

 be borne before the cost of coal would rise to a 

 ruinous figure. 



There are two classes ^ of foreign pit-timber, 

 the statistics of the import of which in 1912 

 were : — 



1. Spruce and common pine 



from Russia, Sweden, and 



Norway ; nearly all from Loads £ 



Baltic ports 1,170,000 ... 2,580,000 



2. Maritime pine from France, 



Portugal, and Spain ... 1,189,000 ... 1,039,000 



- A small quantity, 26,000 loads, from Germany and other countries is 

 not included in the above figur-s. 



