March 13, 1919] 



NATURE 



27 



Bateman's" corpuscular theory of the structure of 

 the electromagnetic field is not out of harmony with 

 this view, and, moreover, his hypothesis has the dis- 

 tinct advantage of accounting for wave-motion as a 

 special case, thus apparently pointing to a method of 

 avoiding those difficulties with interference and diffrac- 

 tion that usually affect corpuscular theories. If we 

 accept the rather preferable 'solid angle" hypothesis 

 instead of a less restricted type of non-uniform radia- 

 tion (such, for instance, as the " specked " wave- 

 front-"), it is not certain just what difficulties might 

 arise in regard to the ultimate trend of planetary 

 temperatures. But certainly the great majority of 

 recorded sidereal phenomena would be unaffected, 

 whether the "solid angle" interpretation is adopted or 

 merely one which requires that radiation should be 

 much restricted outside the solid angle. 



In addition to the possibility of accounting imme- 

 diately for the large discrepancy in the duration of 

 solar and stellar radiation, there would be other 

 decided advantages in a hypothesis of this kind. 



First, we should no longer be confronted with the 

 tragic and almost incomprehensible "waste" of stellar 

 energy. On the ordinary continuity theory, all the 

 sun's radiation, except the one-millionth of i per cent, 

 that falls upon flanets or known stars, ^^ penetrates 

 indefinitely far beyond the regions where now we 

 observe material bodies ; and we recognise no reason- 

 able mechanism for its recovery or rematerialisation. 

 Secondly, we should not have to call upon some 

 unknown source of energy to account for the simplest 

 problems of stellar radiation ; the otherwise happy 

 accordances now existing between astronomical ob- 

 servation and gravitational theories of gaseous bodies 

 would emerge from the shadow of this great doubt. 



Thirdly, among others of less obvious connection, 

 the following outstanding stellar phenomena might 

 find partial or complete explanation : — (a) The remark- 

 able decrease of redness with brightness for the giant 

 stars in globular clusters ^* ; (b) the relation of spec- 

 tral type to brightness for both giant and dwarf visual 

 binaries ; and (c) the low density of the reddish com- 

 panions in eclipsing variable star systems. In all 

 these cases it would be a matter of the ratio of the 

 angle occupied by neighbouring bodies to the total 

 solid angle. 



To summarise :— As commonly interpreted, the 

 Helmholtz-Kelvin contraction, and other but less 

 important known stores of energy, can have main- 

 tained solar radiation for less than twentv million 

 years. On the other hand, it is equally definite that 

 the sun has radiated at its present rate for much 

 more than a thousand million years ; in support of 

 strong geological evidence of a long time-scale, various 

 astrophvsical results mav now be adduced, mainly 

 from observations and interpretations of star clusters 

 and variables. The very pronounced disagreement 

 might be explained either if sources of energy now 

 unrecognised could be discovered in the sun and stars, 

 or if the necessity of modification of the physical 

 theories could be demonstrated. "The search for an 

 additional store of energy is not at all encouraging." " 

 since gravitational, chemical, radio-active, or other 

 electrical sources appear unavailing. If we assume 

 that the radiation from isolated sources, such as 

 sidereal bodies, is not uniformly propagated in all 



19 Proc. ^^at. Acad. .Sci., vol. iv., p. I4o(iqi8): the Messenger of Mathe- 

 iiiatics, N.S., vol. xlvii., p. i6i (1918) ; Phil. Atag., vol. xxxiv., p. 405 

 (1917). The more extended statement of the theory will appear in the 

 Proceedings of the London Mathematical Society. 



■■» Sir J. J. Thomson, Proc. Cambr. Phil. Soc., vol. xiv., p. 41P (1907)- 

 Cf. Jeans, "Report on Radiation and the Quantum-Theory" (London, 

 1914). Dp. 81, 85 ff. 



21 The angle subtended by the large nebulae much exceeds that of stars 

 and planets, but it is very unlikely that the nebulae represent a continuous 

 distribution of matter. 



~ Mt. Wilson Tommnnications, Nos. 19 and 34 (1916), and elsewhere. 



^ Eddington, Nature, vo'. xcix., p. ^^'. (1917). 



NO. 2576, VOL. 103] 



directions," we may find the solution not only to the 

 dilemma of the ages of stars, but perhaps also to 

 other astrophvsical phenomena ; and, conversely, the 

 removal of this serious discrepancy may be proposed 

 as an argument for a corpuscular theory of radiation, 

 in which the direction of other bodies from a radiant 

 source is an important factor. Harlow Shapley. 



Mount Wilson Solar Observatory, Pasadena, 

 California, December 14, 1918. 



RESEARCH AND UNIVERSITY 

 EDUCATION. 



IN his opening presidential address this session to 

 the Royal Society of Edinburgh on "The En- 

 dowment of Scientific and Industrial Research " 

 (Proc. Roy. Soc. Edinburgh, 1919, vol. xxxix., 

 No. i), Dr. John Home discusses the report of the 

 Committee of the Privy Council for Scientific and 

 Industrial Research for 1917-18, and the findings 

 of Sir J. J. Thomson's committee on the position 

 of natural science in the educational system of 

 Great Britain, and then turns his attention 

 nearer home to the results of the Carnegie Trust's 

 research scheme in furnishing trained research 

 workers. He alludes especially to the chemistry 

 department of St. Andrews, which has secured 

 more research scholars and fellows under this 

 scheme than any other educational centre in Scot- 

 land. Its favourable position in this respect is 

 ascribed to the .smallness of the number of 

 students, to specially commodious and well- 

 equipped laboratories, to a private research en- 

 dowment which secures complete freedom of 

 action to the head of the department and has 

 rendered it unnecessary for him ever to approach 

 the University Court for help, to a special field 

 of investigation — the chemistry of sugars — 

 capable of providing unlimited subjects for the 

 training not only of the organic, but also of the 

 physical and bio-chemist, and, lastly, to the initia- 

 tive of the professor in finding industrial positions 

 for the trained workers — it is to be hoped, at a 

 salary that interests the income-tax commissioner. 

 In the larger Scottish universities the science 

 departments struggle under the disadvantages of 

 inadequate laboratories, crowded class-rooms, and 

 overworked and underpaid staffs. One hears, in 

 fact, of nothing now but the duplication of the 

 notoriously large medical classes, and even of the 

 double daily lectures being given by the same 

 lecturer. The Carnegie Trustees are asked 

 seriously to consider whether the funds provided 

 for scientific study and investigation cannot be 

 increased very largely. 



It is interesting to find thus officially recognised 

 a few of the more elementary conditions for the 

 fostering of research. The conclusion that one 

 of the main reasons for the success of the St. 

 Andrews chemical research school is due to the 



■-* [December iS.] Father Rodis has pointed out to me that Poincarrf, in a 

 discussion of the impossibility of regardiiig the sun .is a cooling bodv entirely 

 without power of renewing its heat (" Hypotheses Co-;mogoniques," p. 192), 

 refers to the " solid angle " hypothesis, rejecting it, however, for the reason 

 (which in the present problem does not now appear sufficient) that "at the 

 momentwhen energy leaves the sun it obviously cannot foretell whether or 

 not it will encounter a planet." Poincarii did not consider the discrepancy 

 very serious between geology and the contraction theory, apparently 

 believing that radio-activity would be competent to make up whatever defic 

 of energy migh; exisu 



