346 



NATURE 



| January 



I'M') 



OUR BOOKSHELF. 



Studies in Primitive Looms. By H. Ling Roth. 

 Pari iv. (Banklield Museum.) (Halifax: 

 F. King and Sons.) Four parts, price t,s. each. 

 Mr. Ling Roth has now completed his important 

 technological monograph, of which four parts have 

 recently appeared in the Journal of the Royal 

 Anthropological Institute. In the introduction to 

 the series he remarks that "weaving is generally 

 considered to be the outcome of basketry and mat- 

 making, and in most cases probably it is so." 

 The arrangement of the monograph is geo- 

 graphical, and Mr. Ling Roth discusses the inte- 

 resting problem of the origin of these varied 

 types. Some, he thinks, were invented on the 

 spot, and do not owe their origin to copying or 

 to contact with other races. But this is not always 

 the case. The African varieties — fixed heddle, 

 pit treadle, and horizontal narrow-band — are 

 all probably of Asiatic origin, the last having 

 undergone so many modifications that, compared 

 with its prototype, it is almost unrecognisable. 

 The warp-weighted loom was used in ancient 

 Greece, in the Swiss lake dwellings, and at the 

 beginning of the Bronze age. It appears in Scan- 

 dinavian saga in the eleventh century, and was 

 probably in use by the Northern peoples many 

 hundred years before that time. Mr. Ling Roth 

 has illustrated his monograph with excellent 

 sketches, drawn from all available sources, and his 

 technical knowledge has helped him in discussing 

 the various types. It may be hoped that he will 

 extend his collection of papers, and republish them 

 in a more accessible form. 



Alfred Russel Wallace: The Story of a Great Dis- 

 coverer. By L. T. Hogben. (Pioneers of Pro- 

 gress : Men of Science.) Pp. 64. (London : 

 Society for Promoting Christian Knowledge, 

 1918.) Price 2A\ net. 

 The name of Alfred Russel Wallace is rightly held 

 in honour as that of one who with few advantages 

 of birth or education made for himself a dis- 

 tinguished position as naturalist and traveller, 

 and who, besides adding largely to the acquaint- 

 ance of scientific men with certain regions previ- 

 ously little known, and making extensive collec- 

 tions of their fauna, achieved independently the 

 discovery of natural selection, the most illuminat- 

 ing principle ever enunciated in the history of bio- 

 logical study. It is obvious that the life of such 

 a man cannot be treated adequately in a small 

 book of sixty-four pages, and Mr. Hogben 's 

 volume does not pretend to be more than a sketch. 

 In view, however, of his necessary limits, it is to 

 be regretted that the author has not observed a 

 better proportion in the selection of facts to be 

 recorded. Details of Wallace's early life are 

 interesting in their bearing on his later develop- 

 ment, but we could have spared the account of the 

 arrangement of desks and fireplaces in the gram- 

 mar school at Hertford if Mr. Hogben had given 

 us in its place a few more particulars of the ex- 

 ploration of the Amazon and of the Malayan 

 islands. On the subject of geographical distribu- 

 te 2566, VOL. I02") 



tion the tone of the book is scarcely lair; and 

 on p. 47, besides some careless punctuation, there 

 is a distinct error of fact. With such amiable 

 weaknesses as anti-vaccination and spiritualism 

 we are not concerned, but we greatly miss a more 

 extended account of the work that really made 

 Wallace's reputation. F. A. I). 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



Fuel Economisers. 



I can corroborate Mr. R. C. Parsons's remarks in 

 Nature of December 20 with regard to the ad- 

 vantages of economisers connected with stoves, as I 

 have had them in use for the last twenty-six years 

 with very satisfactory results, the heating being better 

 witli a greatly reduced consumption of fuel. M\ 

 economisers differ from those of Mr. Parsons only in 

 being arranged symmetrically behind the stove, and not 

 to one side of it; and in having an opening in the 

 dividing partition in the box, which is usual!} closed 

 by a damper, but can be opened so as to provide a 

 direct passage for the gases from the stove to the 

 chimney, so giving a better draught to the fire when 

 it is being lit. During these years I have had two 

 stoves and economisers in use here; one is a Gurney 

 slow-combustion stove, which has an economist 1 ol 

 about the same heating area as itself. This stove 

 goes day and night during the cold season. The 

 othei is a common cylindrical slow-combustion stove, 

 ami its economiser has got about twice the healing 

 area of the stove, and is only occasionally used. 



When the Gurney stove was first fitted in, it had 

 no economiser, and the result was unsatisfactory. 

 All the hot air went to the top floor, and the ground 

 floor was but little benefited, as it received only the 

 radiated heat. After the economiser was added condi- 

 tions were entirely changed ; all the ground floor was 

 now much better warmed. The reason for the change 

 is evident when we Consider what takes place under 

 the two conditions. With the stove alone a good fire 

 had to be kept up, and the highly heated air ascended 

 to the highest part in the house, and tended to remain 

 their, where it lost its heat to the ceiling, which is 

 the coldest part of a top room ; but when the econo- 

 miser was added there was double the heating sur- 

 face, so a much larger amount of air was heated, 

 though not to so high a temperature. The hot air 

 did not now have the same tendency to keep near 

 the ceiling and lose its heat there, and the larger 

 volume of hot air put into circulation enabled all the 

 air in the ground floor to be heated. 



These things are better understood in Switzerland, 

 and in other countries where fuel is dear, than is tin- 

 case here. There one frequently sees stoves built of 

 bricks and tiled, 4 ft. or 5 ft. in diameter, and from 

 6 ft. to 8 ft. high, with a small wood fire burning in 

 the centre of them. 



With regard to the common cylindrical stove above 

 referred to, another advantage of the economiser is 

 thai after the fire is lit it at once begins to warm the 

 room, whereas the outside of the stove takps an hour 

 or two to heat through the fire-brick lining, while 

 the economiser is heated and begins to warm tn< 

 room almost at once. 



