December 23, 1920] 



NATURE 



537 



should be put on the market at a reasonable 

 price." The friability of such cokes has proved 

 a grave obstacle, and, if one seeks to avoid it by 

 briquettingf, Mrs. Fishenden's results suggest that 

 any superiority in radiating power would be more 

 than wiped out, while the high cost of pitch — the 

 natural binding material — is not helpful. The 

 Fuel Research Board and private workers are busy 

 with the problem. 



One cannot help thinking that the real domestic 

 smoke problem is presented, not by the grates of 

 the type studied by Mrs. Fishenden, but by the 

 enormously more numerous and more voracious 

 kitchen ranges used for cooking as well as for 

 heating. Would a smokeless fuel prove service- 

 able for these? The present report does not deal 

 with the kitchen range. 



Mrs. Fishenden has exploded several popular 

 fallacies. Powders have been sold (under promis- 

 ing names) which are alleged to effect marvellous 

 economies in fuel, as vouched for by people whose 

 official descriptions ought to have implied better 

 things. Some of these powders were examined 

 and found to be essentially common salt coloured 

 with iron oxide. No appreciable effect on the radiant 

 efficiency of a fire consuming coal treated with these 

 salts could be detected. To-day, when coal and 

 money are so scarce, a protective publicity might 

 well be given to these tests in the daily Press. 



It appears generally from Mrs. Fishenden's 

 work that the wastefulness of the open fire may 

 be lessened by the use 'of carbonised fuel, and 

 particularly by the cutting down of draught 

 so as to limit the air drawn through the room 

 and into the chimney to the quantity required for 

 ventilation. The use of solid fuel is still cheaper 

 than that of gaseous fuel for fires which have to 

 be in constant use. 



Not the least useful part of the report is the 

 appendix, containing a summary of recent biblio- 

 graphy of work on domestic heating appliances. 

 Attention may well be directed to earlier students 

 of the problem — Rumford, Peclet (whose "Traits 

 de Chaleur" still repays perusal), and more re- 

 cently Dr. Pridgin Teale, of Leeds, who may be 

 regarded as the pioneer of, modern grate reform 

 in this country. Peclet, and perhaps Rumford, 

 seemed quite clear about the significance of ex- 

 cessive flue draught and the need for restricted 

 and variable flue openings, and in reading his 

 treatise one can only marvel that the manufacture 

 of crude appliances has continued to the present 

 day. Still, Mrs. Fishenden's work has placed the 

 whole subject on a more substantial foundation of 

 carefully ascertained data, an achievement which 

 should prove valuable in the campaign of smoke 

 abatement and fuel economy, and at a cost which 

 seems to be relatively insignificant. J. W. C. 



A Handbook to Roman Pottery.* 



THE term "terra slgillata," denoting certain 

 well-known classes of Roman pottery, may 

 be unfamiliar to the ordinary reader, but it is 

 gradually coming into use in place of the some- 

 what misleading "Samian ware" of the nine- 

 teenth-century antiquarian. The late Prof. Haver- 

 field, indeed, stoutly upheld the use of the older 

 term ; but it is opcp to decided objections, being 

 purely conventional, unhistorical, and non-descrip- 

 tive. Such expressions as "Roman red-glazed 

 ware," "Gaulish red ware," etc., may be more 

 accurate, but are not sufficiently definitive. The 

 authors of the work under review have, therefore, 

 followed Continental precedent and adopted this 

 term, which strictly denotes "clay decorated with 

 stamped patterns " (from sif;illum, a stamp). The 

 ware with which they deal is the pottery produced 

 under the Roman Empire and found in all parts 

 of Western Europe, which is marked by the use 

 of a fine red paste and a lustrous red glaze, and 

 usually ornamented by means of patterns and 

 figures in relief. 



It is the first attempt made in this country to 

 produce a handbook to the study of this pottery, 

 which during the last twenty years has made a 

 fjreat advance, owing to the labours of British, 

 French, and German arrhseologists. and to the 

 more careful attention paid to the results of .scien- 

 tific excavations in this country. We most heartily 



t "An In!' 



Chr"nolo«t''ai 



Pp. aii + iS6- 



• Prk« 4ti. iwt. 



'it>: Troitd frsai * 

 : T. Dark* Prjrc*. 

 "Mn, ukI Co., 19M.) 



congratulate the authors on their work, which is 

 distinguished both by exhaustive knowledge and 

 by scientific accuracy. 



Their aim has been to arrive at definite con- 

 clusions concerning the development of Roman 

 p)ottery under the Empire by a diligent study of 

 such details of technique, form, decoration, and 

 design as can be of assistance for purposes of 

 dating, and to base on the results of detailed study 



NO. 2669, VOL. 106] 



Kici. 



-V«M of La GraufexDque wan (Form >f) «iih acnll 

 decoiation (about a.d. 40). 



i a general consideration of the evolution of this 

 j (x>ttery and the sources of its inspiration. 



The book is divided into ten chapters, the first 

 two being of a general and introductory nature. 

 Chap. iii. deals with "dated sites" — i.e. those 

 j where the approximate dates of occupation are 

 known, such as Haltcrn in Germany (ii B.C. to 

 A.D. 9). Chap. iv. gives a list of the potters 

 whose names are stamped on the vessels, arranged 

 in chronological groups. In chap. v. the vessds 

 decorated in moulded roliof are discussed under 



