432 



NATURE 



[July 26, 1917 



Solar Prominences. — An important memoir on solar 

 prominences has been published by Mr. and Mrs. 

 Evershed (Memoirs Kodaikanal Obs., vol. i., part ii.). 

 The total number of prominences observed and photo- 

 graphed at the sun's limb at Kenley and Kodaikanal. 

 during the years 1890 to 1914 was about 71,000, and in 

 recent years the denser prominences have also been 

 photographed as absorption markings on the sun's 

 disc. This wealth of observational material is dis- 

 cussed from many points of view. It results, among 

 other conclusions, that there are four belts, two in each 

 hemisphere, which are specially prolific in prominences. 

 The low-latitude belts are coincident with the sun- 

 spot zones, and in these the prominences vary in num- 

 ber with the spots, although direct association of spots 

 and prominences is comparatively rare. In the 

 high-latitude belts the prominences are most 

 frequent between spot minimum and spot maxi- 

 mum ; they reach the pole about spot maxi- 

 mum, and die out there, to form again in 

 latitude ±50°. Magnetic storms appear to be more 

 closely related to spots than to prominences, but it is 

 possible that an overlying prominence is a necessary 

 condition for a spot to produce a magnetic storm. 

 Large high prominences are roughly divisible into 

 four classes, namely, broad massive prominences, 

 tapering forms, diffused forms, and prominences in 

 rows. . Prominences associated with spots take the 

 form of jets, rockets, or arches. The prevailing rocket 

 type suggests the action of an intermittent explosive 

 force in spots, which only partially neutralises gravity, 

 while in the large masses gravity appears to be com- 

 pletely neutralised by the upward force. The density 

 of prominences is probably very low, and it is sug- 

 gested that the luminosity may be due to the internal 

 energy of the atoms, possibly derived mainly by 

 absorption of the intense solar radiation. Numerous 

 photographs of prominences are reproduced. 



FUEL RESEARCH. 



AT the request of the Board of Trade and other 

 Government departments, the Fuel Research 

 Board has undertaken an in\-esligation oh the most 

 suitable composition and quality of gas, and the 

 minimum pressure at which it should be supplied, 

 having regard to the desirability for economy in the use 

 of coal, the adequate recovery of by-products, and the 

 purposes for which coal is now used. The Research 

 Board will also act in an advisory capacity. With the 

 great extension of the use of gas for power and heat- 

 ing, and the possibility of using efficiently for illu- 

 mi-nating purposes, by means of the incandescent mantle, 

 gas of much lower illuminating value than formerly, 

 more importance now attaches to calorific value than 

 to candle-power. Practice has necessarily conformed 

 to the altered conditions, for gas engineers have gorte 

 a good way in solving the problems involved in 

 making the best use of coal in their industry, in the 

 recovery of by-products, on which success so much 

 depends, together with supplying a gas satisfactory 

 for the wide and varied requirements. The industry 

 has indeed been exceptional in the valuable research 

 work done, its enterprise being shown in the estab- 

 lishment of the Livesey Laboratory at Leeds. 



Possibly the Research Board will find little scope 

 for improvement in the general production of coal- 

 gas, although no one would claim that iinalitv has 

 been reached, but some important problems remain for 

 investigation, notably the production of low-tempera- 

 ture coke and the utilisation of the oils and very rich 

 gas produced. The gas engineer has hitherto not 

 regarded this question in an unprejudiced manner, 

 whilst the advocates have generally been over-optim- 

 istic, so that independent investigation is really wanted. 

 NO. 2491, VOL. 99] 



There is also a wide field for investigating how coke- 

 oven gas may be more extensively employed to supple- 

 ment the output of suitably situated gasworks, and 

 the more extended use of water-gas. 



The Fuel Research Board, with the sanction of the 

 Committee of the Privy Council for Scientific and 

 Industrial Research, has appointed a committee of 

 inquiry into the utilisation of Irish peat deposits. The 

 terms of reference to the committee are as follows : — 

 " To inquire into and to consider the experience already 

 gained in Ireland in respect of the winning, prepara- 

 tion, and use of peat for fuel and for other purposes, 

 and to suggest what means shall be taken to ascertain 

 the conditions under which, in the most favourably 

 situated localities, it can be profitably won, prepared, 

 and used, having regard to the economic conditions of 

 Ireland; and to report to the Fuel Research Board." 



Though the inquiries of the committee will ulti- 

 mately lead up to the consideration of peat as a source 

 of energy in central power stations, there are sound 

 reasons why this aspect of the problem should be 

 postponed to a later stage. On one hand, the Fuel 

 Research Board is already organising an extensive 

 inquiry into the problems of fuel economy in connec- 

 tion with power production, and the results of this 

 inquiry will supply the fundamental data and informa- 

 tion which will be required when the time comes for 

 the consideration of any wide scheme of development 

 in Ireland. On the other hand, any schemes of de- 

 velopment must be based on a more exact knowledge 

 than is at present available regarding the selection 

 of the more favourably situated bogs and the possi- 

 bilities of winning and transporting partially dried peat 

 to centres at which it may be converted into market- 

 able products. It is obvious, therefore, that the in- 

 quiries of the committee are likely to be most fruitful 

 if they are concentrated on the fundamental problems, 

 for until these are settled no satisfactory progress 

 can be made. 



The following appointments have been made to the 

 committee : — Sir John Purser Griffith (chairman), 

 Prof. Hugh Ryan, Prof. Sydney Young, Mr. George 

 Fletcher, and Prof. Pierce Purcell (secretary). All 

 communications should be addressed to the Secretary, 

 The Peat Inquirv Committee, University College, 

 Dublin. 



GLASS TECHNOLOGY. 



T^HE newly formed Society of Glass Technology is 

 -*• to be warmly congratulated on the first number 

 of its Journal, which has just appeared. The volume 

 contains five original papers and a considerable num- 

 ber of abstracts dealing with glass and allied subjects. 

 These abstracts, in which an endeavour is made to 

 summarise the literature of the subject — including that 

 appearing on the Continent so far back as the begin- 

 ning of 1915 — form a most valuable feature, particu- 

 larly as the difficult work of abstracting has been well 

 done. If, at a later stage, the society could under- 

 take to carry the abstracts back — if possible for a 

 period of ten years — they would earn the gratitude of 

 all concerned with glass. There is, of course, always • 

 the difficulty in such abstracts of discriminating be- 1 

 tween the wheat and the chaff, so as to avoid burden- * 

 ing the pages with abstracts of valueless material; 

 such discrimination, however, demands a degree of 

 intimate familiarity with the subject in both its indus- 

 trial and scientific aspects "which is scarcely obtainable 

 in the case of glass, since this has only recently begiin 

 to receive in this country the attention which it de- 

 serves. It is, further, a little doubtful whether the 

 editor of this Journal has been wise in including ab- 

 stracts on purely optical subjects, since these are mor^ 



