NATURE 



THURSDAY, MAY 12, 1904. 



SA^nXRY ENGINEERING. 

 Refuse Disposal and Power Production. By W. 

 Francis Goodrich, A.M. Inst. M.E. Pp. xv + 384. 

 (Westminster: Constable and Co., Ltd., 1904.) 

 Price 16s. net. 



THE destruction of town refuse by fire is a com- 

 paratively modern development; the first 

 furnaces erected for such a purpose were constructed 

 to the designs of Mr. Fryer at Manchester in 1876, and 

 these furnaces, though considerably modified, are still 

 at work. The gross insanitary character of the 

 ordinary' system of refuse disposal is patent to every- 

 one who has occasion to move about in the neigh- 

 bourhood of any of our large cities ; the refuse is de- 

 posited in tips ; often an old quarry or gravel 

 pit is selected for this purpose, and the refuse 

 is dumped into these cavities until they are 

 filled up. How unsatisfactory this is has been 

 proved by the fact that outbreaks of disease 

 have occurred directly traceable to the existence 

 of these heaps of abomination. The author states that 

 an outbreak at Fratton was certified by the medical 

 authorities to be due to the contagion brought by flies 

 bred in the pestiferous heaps of Portsmouth refuse 

 which had been deposited in this neighbourhood. 

 These refuse heaps in the summer time breed ffies in 

 millions, and they are the constant resort of rats, 

 which spread from them, all over the neighbourhood, 

 and how readily most dangerous diseases are dissemin- 

 ated by both these agencies is well known to all 

 medical authorities. We had this fact brought home 

 to us clearly during the late campaign in South Africa, 

 when the nurses and doctors in the field hospitals were 

 frequently able to tell that a patient being brought in 

 was a typhoid sufferer from the swarms of flies round 

 him. 



Fortunately the Local Government Board is setting 

 its face steadily against a continuation of this in- 

 sanitary practice, and the recent example at Bury St. 

 Edmunds, quoted by Mr. Goodrich, where the board 

 refused to sanction a loan for the purpose of pur- 

 chasing land for a tip, is a striking illustration of this 

 modern tendency. Refuse tipping at sea, owing to 

 the fact that much of the refuse is liable to be washed 

 back on the foreshore, and also that it has frequently 

 to be stored for lengthy periods owing to stormy 

 weather, is an equally unsatisfactory method. 



The book is fully illustrated, and two or three of 

 the illustrations, reproduced from photographs, show 

 the filthy state of affairs brought about by town 

 authorities neglecting to avail themselves of modern 

 appliances. The author discusses very fully the 

 various systems of burning refuse in destructors which 

 have been adopted in this country, for it is chiefly in 

 Great Britain that fire purification has been adopted, 

 and the various systems of charging the refuse into 

 the destructor cells are described in detail ; the direct 

 charging systems are compared very fairly with the 

 hand or shovel feeding systems. 



Though the former, from the sanitary point of view, 

 NO. 1802, VOL. 70] 



naturally appears the more desirable, there can be 

 little doubt from the figures given by Mr. Goodrich 

 that there is not much economy in labour by the adop- 

 tion of direct charging, since the labour of dragging 

 the material from the drying hearth forward on to the 

 grates is greatly increased. The first types, founded 

 on a system of natural draught and low temperatures 

 in the cells, undoubtedly did much to retard the de- 

 velopment and the introduction of destructors, and in 

 this connection to Mr. Charles Jones, of Ealing, must 

 be given much credit, because his cremator certainly 

 led the way to the design of the modern forced draught 

 high temperature destructor. 



Illustrations and descriptions are given of most of 

 the destructors which have been used up to 

 the present time, and then the author deals 

 exhaustively with the labour cost in the different 

 systems, with the utilisation of the clinker, and with 

 the application of the steam generated to electricity 

 works, sewage works, or waterworks. The figures 

 given for the labour cost show very striking- variations 

 in the different towns, ranging from as low as 6|d. per 

 ton of refuse burnt to as high as 2s. lod. ; the higher 

 cost in a few cases arises from the fact that the quantity 

 of refuse to be destroyed is comparatively small, and 

 therefore the three shift, eight hour system, which is 

 the more economical, cannot be adopted. 



The disposal of the clinker no longer presents any 

 real difficulty, as in the modern destructor the tempera- 

 ture is easily kept high enough and sufficiently steady 

 to produce a thoroughly hard, well burnt clinker suit- 

 able for many purposes. The late Mr. J. McTaggart, of 

 Bradford, did much in directing attention to the various 

 uses to which the clinker could be applied, and the 

 results he obtained were remarkable ; clinker bricks, 

 clinker tiles, clinker mortar, clinker concrete were 

 some of the products into which his waste material 

 was converted, and Bradford led the way in showing 

 that by the utilisation of this residuum, which amounts 

 on an average to about one-third of the weight of the 

 total refuse consumed, much of the cost of running a 

 destructor can be repaid. The utilisation of the steam 

 generated has also made great strides during the past 

 few years, and at the present time there are, the author 

 states, sixty combined electricity and destructor works 

 either running or under construction in this country, 

 several of them of considerable size, the electricity 

 generated being used both for lighting and for 

 traction. 



The author gives a comparative statement showing 

 the number of electrical units generated per ton of 

 refuse destroyed in twenty of these stations, the figures 

 ranging from as low as 15 to as high as 80 per ton 

 of refuse burnt. He quotes, from reports of station 

 engineers, opinions which show conclusively that 

 whatever difficulties may have been experienced at 

 first, owing to variations in the steam pressure, at the 

 present time it is quite as easy to run a plant satis- 

 factorily with steam produced from the waste heat of 

 the destructor furnaces as when generated in an 

 ordinary boiler using coal or other fuel. About thirty- 

 eight towns are using steam from the destructors for 

 driving pumping plants in connection with sewage dis- 



C 



