.SYA" WILLIAM SIl-.MENS, F.R.S. 129 



labour in the production of iron and steel, comes cheap fuel, a 

 subject to which, as you are aware, I have devoted considerable 

 attention, and I would therefore treat it, with your permission, 

 mther more fully than other subjects of perhaps equal importance'. 

 Fuel, in the widest acceptation of the word, may be said to com- 

 prise all potential force which we may call into requisition for 

 effecting our purposes of heating and working the materials with 

 which we have to deal, although in a more restricted sense it com- 

 prises only those carbonaceous matters which, in their combustion, 

 yield the heat necessary for working our furnaces, and for raising 

 steam in our boilers. It may safely be asserted that the great 

 supply of energy available for our purposes has been, or is being, 

 derived from that great orb which vivifies all nature the sun. In 

 the case of coal, it has been shown that its existence is attributable 

 to the rays of the sun, which in former ages broke up or dissociated 

 carbonic acid and water in the leaves of plants, and rendered the 

 carbon and hydrogen, thus separated from the oxygen, available 

 for re-combustion. The same action still continues in the forma- 

 tion of wood, peat, and indeed all vegetable matter. 



The solar ray produces, however, other forms of energy through 

 the evaporation of sea water, and the resulting rainfall upon 

 elevated lands, and through currents set up in the atmosphere and 

 in the sea, which give rise to available sources of power of vast 

 aggregate amount, and which may also be regarded in the light of 

 fuel in the wider sense. 



The form of fuel, however, which possesses the greatest interest 

 for us, the iron-smelters of the 19th century, is without doubt the 

 accumulation of the solar energy of former ages, which is em- 

 bodied in the form of coal, and it behoves us to inquire what are 

 the stores of this most convenient form of fuel. 



Recent enquiry into the distribution of coal in this and other 

 countries has proved that the stores of these invaluable deposits 

 are greater than had at one time been supposed. 



I have compiled a table of the coal areas and production of the 

 globe, the figures in which are collected from various sources. It 

 is far from being complete, but will serve us for purposes of 

 comparison. 



VOL. III. 



