;oo 



NATURE 



[January 5, 191 1 



Heathen begins with an account of the various 

 branches of the textile and other trades, deeply in- 

 teresting:, not only to those desiring a knowledge of 

 their history, but to all students of the economic posi- 

 tion at that time. One curious fact impresses itself 

 on the mind of the reader, that is, how greatly the 

 development of trade was hindered by the very means 

 used to encourage certain particular trades which were 

 protected by Government action. There was cer- 

 tainly no laissez-faire in those davs. 



The most important and most ancient of British 

 manufactures was the woollen industry. It was in a 

 state of great prosperity in the eighteenth century, 

 and was even down to 1770 a domestic industry car- 

 ried out in the homes, of the farmers, who produced 

 the wool, and carded, spun, and wove it into cloth by 

 the help of their families and servants. Nearly all 

 farmers depended on this industry to enable them to 

 pay their rent. For its protection enactments were 

 passed to prevent the export of the raw material ; laws 

 were also passed to prevent the mixture of cotton and 

 wool or of linen and wool in weaving fabrics. It was 

 to prevent competition with this valuable trade that 

 one of the Parliaments of that period killed the Irish 

 woollen trade, particularly its blanket trade, by put- 

 ting an import duty on its roods. Sir Henry Wood 

 does not mention this fact, but he states that the 

 encouragement given to the Irish linen industry was 

 to prevent that country entering into competition with 

 England. In the eighteenth century, as now, Ireland 

 and Scotland seem to have been the chief manufac- 

 turers of linen. 



Probably it was owing to these repressive regula- 

 tions that England was one of the last countries to 

 adopt the manufacture of cotton. The skill of her 

 spinners was only equal to producing verv coarse 

 cotton yarns. Beautiful muslins and calicoes were 

 imported from India, and became so popular that in 

 1760 it was made "penal for any woman to wear a 

 dress made of India calico." The wearing of French 

 cambrics was also penal. One of the most fascinating 

 sections of this volume contains the description of the 

 gradual growth of the cotton industry as machinery 

 was invented and perfected. 



The making of linen and afterwards of cotton 

 thread was first initiated in the west of Scotland by a 

 woman named Christian Shaw; it rose to be an im- 

 portant trade, even in the eighteenth century, and its 

 products were largely imported to England for pur- 

 poses of lace making, then chiefly carried on in 

 Devonshire and Bucks. 



At the beginning of the century under discussion the 

 manufacture of iron was at a very low ebb. Carried 

 out since Roman times by the use of charcoal derived 

 from wood, it had almost declined entirely owing to 

 the destruction of the woods, and consequent legisla- 

 tive restrictions. The author traces the gradual 

 development of the use of coal for smelting, beginning 

 about 1735, at Coalbrookdale, first of all. 



At this same place the method of casting iron was 



discovered and practised. Sheffield and Birmingham 



were already making a reputation for metal goods, 



including pewter, which was much used as a subsa- 



NO. 2149, VOL. 85] 



tute for pottery. Until well into the middle of the 

 century England was. n>ainly dependent on France and 

 Holland for the commonest kinds of earthenware. 



Sir Henry Wood tells us that this period, until 

 some time after the middle of the century, was not a 

 happy one for science or for scientific development, 

 and we therefore find that industries dependent on 

 scientific knowledge, such as the making of glass and 

 fine pottery, of brewing and other chemical processes, 

 were in a backward state. 



Enough has been said to show what a wealth of 

 material has been skilfully put together, and this book 

 forms a most trustworthy source of information when 

 coming from one who is in such a position as the 

 secretary of the Royal Society of Arts. 



SPECTROSCOPY. 

 The Spectroscope and its Work. By Prof. H. F. 

 Newall, F.R.S. Pp. 163 + viii Plates. (London : 

 Society for Promoting Christian Knowledge, 19 10.) 

 Price 2s. 6d. 



ALTHOUGH classed as a manual of elementary- 

 science, this little volume will be found to cover 

 a very wide range of the phenomena of spectroscopy. 

 The opening chapters are occupied with the first prin- 

 ciples of the undulatory theory, Newton's classic 

 experiments, and the description of a simple spectro- 

 scopic outfit. In chapters iv. and v. the reader is 

 introduced to the various types of emission spectra 

 shown by radiations from various sources, and to the 

 characteristics of absorption, including the solar 

 fraunhoferic and chromospheric spectra. Chapter vi. 

 deals verj' lucidly with the theoretical principles to be 

 considered in the design of spectroscopic equipment, 

 showing the relation between angular and linear dis- 

 persion, purity and resolving power of various disper- 

 sive media, &c. Coming next to the application of the 

 spectroscope to definite branches of research, it is 

 shown how, by the aid of large instruments of special 

 design, the spectra of the stars may be studied, re- 

 vealing their variation in chemical constitution. This 

 naturally leads to the s\'stems of classification which 

 have been proposed to deal with the complex group- 

 ings. In describing the fluted structure of the third- 

 type stars, such as a Orjonis, it would have been 

 more correct to speak of the maxima of absorption 

 being nearest to the violet instead of saying that the 

 brighter ends were towards the red, as it is usual to 

 regard the heads of flutings as taken for reference 

 to the positions of flutings. It is also perhaps unfor- 

 tunate for the student that so much space should be 

 given to the old, incomplete, and now little used 

 classifications, while the more comprehensive and 

 natural systems put forward of recent years are dis- 

 cussed in a few lines. The idea suggested on p. 81 

 that the maxima of the star Mira (o Ceti) are of the 

 nature of a conflagration is scarcely to be recom- 

 mended, especially when dealing with beginners, as 

 the practically unchanging character of the spectrum 

 of the star (apart from brilliancy) even at maxima pre- 

 cludes the probability of any such chemical changes 

 as must accompan)' the production of flame. 



