November 10, 1922] 



SCIENCE 



553 



iuereased strength of construction are obtained by 

 a novel design which provides for the heating and 

 regeneration of the coke and pusher ends of each 

 oven as separate units. In this construction, gases 

 of combustion pass over the top of each oven and 

 down through the opposite flues of the same end, 

 instead of passing longitudinally to the end of 

 the same line of flues. Details of design -will be 

 fully illustrated by means of lantern slides. 



Methods for studying the macrostructure of 

 ooTce: Harold J. Bose. The study of the struc- 

 ture of coke has been greatly neglected, due 

 largely to the difficulties involved in preparing 

 specimens, and in satisfactorily reproducing the 

 structure photographically. This paper opens the 

 way to the comprehensive study of coke macro- 

 structure, by the use of iiovol methods. After 

 sectioning the coke, the author impregnates the 

 cut surface with a white hydraulieally hardening 

 compound, after which it may be polished to any 

 desired degree. The excellent contrast of black 

 coke with white impregnating compound makes 

 detailed study and reproduction an easy method. 

 Another novel method is the direct reproduction 

 of the coke surface as obtained by inking the 

 polished coke surface and printing with it on 

 enameled paper. The article is copiously illus- 

 trated with macrophotographs. 



A new electric furnace for the determination of 

 the 'by-product yields of coal: Harold J. Eose. 

 The by-product yields obtainable from coal when 

 coked in a by-product coke oven • may be deter- 

 mined by laboratory distillation tests. Since the 

 yield of by-products is seriously affected by small 

 variations in distillation conditions, the labora- 

 tory determination requires the most rigidly con- 

 trolled testing conditions. For this purpose a 

 furnace, consisting of a deep trough formed from 

 a number of U-shaped electrical heating units 

 with individual control, has Ijeen developed, and 

 is in regular use for research and testing pur- 

 poses. Typical results- are given to show the 

 agreement of duplicate determinations made with 

 this apparatus. The furnace is described and 

 fully illustrated. 



The combustion of coal vjhich lias been a long 

 time in storage: S. W. Parr and T. E. Latns. 

 It has been fairly well demonstrated that coal in 

 storage . does not lose any appreciable number of 

 heat units. Previous investigations shov.' tlie 

 seeming loss in B.T.U. to be due to a correspond- 

 ing increase of weight resulting from absorbed 

 oxygen. However, when coal, especially fine ma- 

 terial which has been long in storage, is burned, 

 the result is very likely to show a low efficiency 



and indeed such coal sometimes seems to be un- 

 willing to burn at all. The results noted in this 

 paper account for the behavior of such coal to 

 be due to the fact that coal in the finer sizes, 

 especially coal of tlie mid-continental type, has a 

 very large absorptive capacity for oxygen, that, 

 because of the colloidal character of the coal sub- 

 stance such absorbed or adsorbed oxygen is held 

 so tenaciously that when discharged by heat it has 

 reached the combining stage and goes off as GO2. 

 The blanketing effect of this gas over the fuel bed 

 results in a deadening of the fire and a loss of 

 efficiency. 



A study of solvents for the separation of coal 

 into its type constituents: E. S. Fisher with 

 S. W. Parr. The greatest advance in coal studies 

 during recent years has resulted from the use of 

 solvents wliich separate the coal into its type 

 constituents without decomposition of their chem- 

 ical structure. British and continental investiga- 

 tors have made much use of pyridine, which, how- 

 ever, seems to lack this prime reciuirement of a 

 true solvent in that it enters into chemical reac- 

 tion with certain of the coal constituents. The 

 work here described gives data in the use of ben- 

 zene, toluene and xj-lenej with methods for the 

 use of the latter solvent which excels all others 

 in the amount and completeness of removal of . 

 the soluble material. This is a preliminary report 

 only as the work is being actively followed up be- 

 cause of the promise of larger yields more easily 

 recovered than by methods in vogue heretofore. 



The softening point of coal — its determination 

 and 'significance: T. E. Latng, W. S. Hawthorne 

 and A. W. Cofpman, with S. W. Parr. Eefer- 

 ences to the softening point of coal are frequent 

 in fuel literature. The term heretofore has had 

 a very vague meaning. This paper describes a 

 method for its determination at once simple and 

 accurate. The interesting fact has been devel- 

 oped that under uniform conditions the softening 

 point repeats itself with marked coustancj'. More- 

 over, it is evidently a charaet^-ristic factor for 

 varj'ing types of coal as also for coal which has 

 been for different lengths of time in storage. 

 That is to say, it is a value which runs parallel 

 with the oxygen content. I^o less striking is the 

 solidifying temperatures, which result in a curve 

 symmetrical with the range exhibited for the 

 softening-temperatures. Description of the ap- 

 paratus with results on numerous coals are given. 

 The results are exceedingly interesting and may 

 answer such questions as : What is the type of. 

 coal? What would be its behavior in storage? 

 What kind of coke would it make and what modi- 



