September 29, 1892] 



NA rURE 



529 



it is in the samedirectioa that we are to look fjr trae economy 

 in the use of coal. The completion of the system of electric 

 lighting in towns is therefore to be desired by the community, 

 not only on account of its great and obvious advantages for illu- 

 mination, but because it will render possible the provision and 

 distribution of a cheap gas for heating purposes ; and the share- 

 holders in gas companies of such fortunate towns should specially 

 rejoice, as herein lies a good prospect not merely of maintaining, 

 but of considerably increasing, their dividends. Gas companies 

 would not only become purveyors of heat energy for domestic 

 use, but for manufacturing purposes as well, not excepting the 

 production of the electric light. 



Hence, our duty to posterity and our own immediate in- 

 terests coincide in requiring the use of more economical methods 

 of using coal, and that which gives promise of the greatest num- 

 ber of advantages involves the conversion of coal as far as 

 possible into gaseous fuel.^ 



I turn now from coal to peat, which is, as you know, a much 

 less mineralized solid fuel. It is obvious that the question of peat 

 utilization is one of much importance in Ireland, as nearly one- 

 seventh of the island is bog. About 1,250,000 acres are mountain 

 bog, and 1,575,000 acres are occupied by flat bogs, which occur 

 over the central limestone plain of the country and stretch away 

 to the north-west. This store of peat is an asset which may 

 become valuable when you shall have exhausted your coal-beds 

 some 170 years hence. We would naturally desire to realize a 

 portion of our assets at a much earlier date, as nearly all the 

 coal used in Ireland must be brought from the eastern side of 

 St. George's Channel. In this fact I think you have some ex- 

 planation of the depressed industrial condition of the country, as 

 manufactures involving the use of much fuel can only flourish in 

 Ireland if the margin of profit be considerable ; where the mar- 

 gin is small and competition keen (as in the greater industries), 

 they must go under in the struggle with manufacturers having 

 cheaper fuel at command. I grant at once that this is no 

 adequate explanation of the absence of many chemical manu- 

 factures which do not involve large consumption of fuel, but it 

 is the inevitable result in the cases to which my remarks 

 apply. 



Peat alone, however well prepared, compares very un- 

 favourably with coal in several particulars : — 



It is a very bulky fuel, in its ordinary condition occupy- 

 ing rather more than five times the space of an equal weight of 

 coal. 



2. It contains from 15 to 25 per cent, of water and seldom 

 less than 10 per cent, of ash. 



3. At least 2\ tons of average peat are required to perform 

 the fame work as one ton of average Staffordshire coal in ordi- 

 nary fireplaces or furnaces. 



Hence the general use of ordinary peat is attended by the 

 disadvantages of requiring much greater storage room than coal, 

 of producing a light and troublesome ash, and requiring more 

 than thirteen times the bulk of coal to produce the same thermal 

 effect. The last-mentioned consideration practically precludes 

 its use in ordinary furnaces where heat of high intensity is re- 

 quired. 



Now the force of the first objection to the use of peat, that 

 of bulk, can be materially diminished by mechanical compres- 

 sion. Many excellent examples of compressed peat have been 

 produced at various times, the most coal-like product I have 

 seen being that of Mr, Hodgson, of Derrylea, who compres;ed, 

 thoroughly disintegrated, and dried peat in heated cylinders, and 

 by partially carbonizing under pressure secured the cementa ■on 

 of the material. Moreover, the ash of such compressed p. at 

 was not so bulky as that of the ordinary fuel. 



I need scarcely say that the intensity of the heat obtainable 

 with compressed peat is greater than with the loose material, 

 but the actual thermal eff.:ct is not much altered, save in so far 

 as the material is drier and therefore less heat is lost in evapo- 

 rating moisture. 



Extended comparative trials, of coal and of good dense peat 

 in steam engines have shown that the work done by one ton of 

 peat was not more than 45 per cent, that of one ton of coal ; 

 hence if coal were i8j. per ton, peat could not compete with it 

 under the most favourable conditions unless delivered at not 

 more than 85. per ton. Now the peat used in these trials did 

 not contain more than 12 per cent, of moisture, but as dug from 



'Since the above was vvritten I have seen a short abstract of Mr. Valon's 

 address to the Institute of Gas Engineers, in which I am glad to find that 

 he takes a somewhat similar view of the si:uation to that exprcised above. 



the bog it seldom contains less than 35 per cent, of water, even 

 when cut from a comparatively dry bog ; it must then be stacked 

 and air-dried. The present price of ordinary turf deliverei at 

 the bog is about ^s. per ton ; when to this is added the cost of 

 handling this bulky fuel, and carriage for fifty miles, the cost 

 exceeds 45 per cent, of that of coal even at inland towns ; hence 

 there is no real economy in the use of peat of the common kind 

 in ordinary furnaces and grates instead of imported coal. 



But the public are led by promoters of peat-minufacturlng 

 companies, and others who should know better, to suppose that 

 by certain processes of disintegration and compression peat can 

 be made to approach very closely in fuel value to an equal 

 weight of coal. There is no doubt that a better looking and 

 denser product can be obtained by these means, and one which 

 requires less storage room ; but unless artificially dried as well, 

 the actual heating effect of the fuel is not materially altered. I 

 have no doubt that the cost of winning and treating the rough 

 peat could be much reduced by the use of suitable labour-saving 

 machinery ; but all methods with which I am acquainted invol- 

 ving artificial drying as well as mechanical compression, have 

 cost so much that the product could not compete with coal at 

 the ordinary level of prices. As I have already said, the Irish 

 peat forms a valuable asset, but one not capable of being realized 

 on any considerable scale at present ; at least when used as fuel 

 in the ordinary way as a substitute for coal. But it is possible 

 to so burn peat that it shall compare much more favourably with 

 coal, and this solution of the problem is obtained by converting 

 rough peat into gas. 



You doubtless remember that in 1872 the cost of coal ad- 

 vanced even beyond the panic prices which prevailed for a week 

 or two about the beginning of the present year. But the coal 

 famine of 1872 lasted for a considerable time, and serious efforts 

 were then made in Ireland for the utilization of peat. It soon 

 became evident that the continuance of dear coal meant the 

 suspension of several industries and their probable loss to the 

 country ; hence, leaving to others the attempts to convert peat 

 into a suitable fuel for general domestic use, I took up the in- 

 dustrial side of the problem. 



I saw that the best chance for economically applying peat 

 for most manufacturing purposes lay in gasifying the material in 

 a Siemens furnace, as two special and important advantages 

 must obviously be gained thereby :— (i) The use^of peat in the 

 rough state without artificial drying ; (2) The avoidance of the 

 injurious efTects of abundant ash by burning the peat-gas at 

 some distance from its source, and under such conditions that 

 the comparative value of coal and peat should be nearly in the 

 proportion of their percentages of carbon. I therefore moved 

 the Royal Dublin Society to appoint a committee of engineers 

 and other scientific men to have the value of peat tested in the 

 way proposed. The outcome was that the directors of the 

 Great Southern and Western Railway of Ireland, acting on the 

 recommendation of the able locomotive engineer, Alexander 

 Macdonnell, C.E,, decided to erect a complete Siemens regene- 

 rative gas furnace for working up scrap iron in their engine 

 factory at Inchicore. This furnace was supplied only with 

 rough peat, often containing as much as 38-40 per cent, of 

 water, but no difficulty was found in keeping the welding chamber 

 at a bright white heat for months at a stretch. The average con- 

 sumption of fuel was 5*09 tons of peat for each ton of iron forged 

 from scrap to finished work. Before the Siemens furnace was built 

 theordinaryairfurnacefed with coal was employed, and the average 

 consumption per ton of iron was 4 "96 tons of coal. I need scarcely 

 say that peat is practically useless in such a furnace. There- 

 fore peat used in the gas furnace as compared with coal in the 

 ordinary welding furnace not only proved in practice to answer 

 extremely well, but performed 97 per cent, of the work done by 

 an equal weight of coal. As the price of peat was about half 

 that of coal at the time, Mr. Macdonnell estimated that a saving 

 of £^ Ts. 9</. per ton of finished forgings was effected. If there- 

 fore the coal beds were exhausted we have a good substitute in 

 peat for operations in which a very-high temperature is required, 

 provided the fuel is used in the gas furnace or according to some 

 similar plan.^ 



The above remarks refer to work done twenty years ago. 

 Now, thanks to the valuable investigations of Mr. Ludwig Mond, 

 F.R.S., detailed in his Presidential Address of 1889, the pro 



» Ofcourse the comparison is more favourable to coal when the latter is 

 used in the Siemens fu'nace, as it is found that a ton of iron required aa 

 average of three tons of coal, therefore th? w >rk don-i by peat was about 

 60 per cent, of that by coal under the same conditions. 



NO. II 96, VOL. 46] 



