July i, 1920] 



NATURE 



551 



would have the outstanding- advantage of smoke- 

 less combustion, but its ash content would, of 

 necessity, be hig-her. It would have the great 

 disadvantage of crushing more easily than 

 ordinary coke in all the processes of transference 

 from the retort to the consumer, but would be 

 correspondingly easier to ignite. Like both raw 

 coal and ordinary coke, it w^ould deliver potential 

 heat units at a cheaper rate than they are supplied 

 in gas. The question of efficiency in use remains, 

 and the report deals benevolently with the effi- 

 ciency obtainable from coal and coke in the most 

 widely used domestic appliance — the open fire. It 

 is set out that with an open fire, which has 

 apparently a chance of regaining a lost reputation 

 if it will only consent to provide a market for 

 large quantities of soft coke, "probably 30 to 40 

 per cent, of the heat escapes completely, 60 to 70 

 per cent, being used in warming the room itself 

 and the general fabric of the building-." 



On this point careful statement is advisable. 

 In view of the comparative unavailability of any 

 heat from the coal fire which is not given up to 

 the room, it would be quite wrong to take 60 to 

 70 per cent, as being the thermal efficiency of the 

 open fire, just as it would be wrong in the other 

 direction to take the radiant efficiency of such a 

 fire (about 25 per cent.) as the total efficiency. 

 Comparative tests are probably best made on 

 radiant efficiency, and it is not surprising to find 

 that the tests made by Dr. Fishenden and quoted 

 in the report are made on this basis. Dr. Fishen- 

 den's tests on coal and coke fires have been carried 

 out at Manchester by the method worked out at 

 the University of Leeds for testing- the radiant 

 efficiency of g"as fires, with such modifications as 

 were found necessary. The work has undoubt- 

 edly been carried out with care and skill, but it 

 should be borne in mind that, on account of the 

 varying condition of a coal fire during the course 

 of a determination, the quantity and distribution 

 of radiation from it cannot be measured with any- 

 thing like the same degree of precision as with a 

 gas fire. Dr. Fishenden does seem to be satisfied, 

 however, that the radiant efficiency of the coke 

 fire is higher than that of the coal fire, and, 

 according to the report, "the radiant efficiency 

 of coal fires of different types varies from 19^ to 

 25 per cent., while, with fires of low-temperature 

 coke in the same grate and burning under the 

 same conditions, this amounts to 31 to 34 per 

 cent." It may be noted that the radiant efficiency 

 of a modern gas-fire is approximately 45 to 50 per 

 cent., but the report does not fail to point out 

 that the real thermal advantage of the gas fire is 

 much greater than would be indicated by any 

 such comparison, because it can be used almost 

 immediately at full efficiency for any period of 

 time, great or small, this, of course, apart from 

 any question of labour-saving and cleanliness. 

 Cooking ranges were brought under test by Mr. 

 A. H. Barker, and his reports are summarised in 

 an appendix. "Mr. Barker lays stress on the 

 extravagance in fuel involved by the necessity of 

 heating- the whole apparatus in the use of only 

 NO. 2644, VOL. 105] 



one or possibly two of its appliances," and points 

 out the further difficulty of obtaining high economy 

 under ordinary working conditions because of the 

 large excess of air employed. 



It is plain that, whether coke or g-as is used as 

 a means of replacing- raw coal for domestic uses, 

 the smoke nuisance would be abated, and a section 

 of the report given under the head " Air Pollu- 

 tion " shows this aspect of the fuel problem to 

 be receiving attention from the Board. The 

 pioneer work of Prof. J. B. Cohen (which should 

 not be overlooked) was of great service in direct- 

 ing attention to the considerable quantity and evil 

 effects of smoke in our atmosphere, and observa- 

 tions have since been multiplied by the Atmo- 

 spheric Pollution Committee of the Meteorological 

 Office, Dr. J. S. Owens, Mr. William Thomson, 

 and others whose work is referred to in this report. 

 The appointment of properly trained inspectors 

 whose help and advice would be welcomed by in- 

 dustrial consumers of fuel is advocated, in addition 

 to the establishment in every large works of an 

 organised fuel control as the "only solid founda- 

 tion on which to build more revolutionary or 

 further-reaching methods of fuel economy." 



It is pointed out usefully that soot from the 

 burning of raw coal, ash and dust from the burn- 

 ing- of coal or coke, and acid impurities derived 

 from the sulphur contained in coal, coke, and 

 unpurified gas, are all to be taken into account in 

 a consideration of atmospheric pollution resulting 

 from the use of fuel, and it may be emphasised 

 that the liability to pour out large quantities of 

 fine ash into the atmosphere is not to be over- 

 looked in considering- the advantages and disad- 

 vantages of pulverised fuel. The use of pulverised 

 coal has not been developed in this country to 

 the same extent as in America, and, therefore, 

 although the Board is putting down a small plant 

 in order to make experiments at East Greenwich, 

 it has thought it advisable to secure full informa- 

 tion upon the subject through a report made by 

 Mr. Leonard Harvey after a special inquiry con- 

 ducted in America. Mr. Harvey visited im- 

 portant installations and collected there the ex- 

 periences and views of the leading consumers of 

 pulverised coal. His report has already been 

 issued separately. "The advantages of the 

 method as an almost perfect means of burning coal 

 must be weighed against the cost of producing 

 and handling coal-dust and the difficulties which 

 may have to be overcome in dealing with its 

 ash." 



Another special inquiry has been directed to the 

 subject of peat. This work has been carried out 

 mainly in Ireland, and has undergone vicissitudes, 

 but a beginning seems to have been made, and 

 reference is made to a paper, read before the 

 Royal Dublin Societv in March last, in which Prof. 

 Purcell gave an admirable summary of the peat 

 situation, not only in Ireland, but also in other 

 countries. It is interesting to note, as indicating 

 elasticity of method, that this paper will be printed 

 as one of the special reports of the Fuel Research 

 Board, and also that the help of the Department 



