August 4, 1887] 



NATURE 



321 



the fact that clouds are not distributed promiscuously at 

 all heights in the air, but that they have, on the contrary, 

 a most decided tendency to form at three definite levels. 

 The mean summer level of these three stories of clouds at 

 Upsala has been found to be as follows : low clouds — 

 stratus, cumulus, cumulo-nimbus, 2000-6000 feet ; middle 

 clouds — strato-cirrus and cumulo-cirrus, 12,000-15,000 

 feet ; high clouds — cirrus, cirro-stratus, and cirro-cumulus, 

 20,000-27,000 feet. 



It would be premature at present to speculate on the 

 physical significance of this fact, but we find the same 

 definite layers of clouds in the tropics as in these high 

 latitudes, and no future cloud-nomenclature or cloud- 

 observations will be satisfactory which do not take the 

 idea of these levels into account. 



But the refinements of the methods employed allow the 

 diurnal variations both of velocity and altitude to be 

 successfully measured. The velocity observations con- 

 firm the results that have been obtained from mountain 

 stations — that, though the general travel of the middle and 

 higher clouds is much greater than that of the surface 

 winds, the diurnal variation of speed at those levels is the 

 reverse of what occurs near the ground. The greatest 

 velocity on the earth's surface is usually about 2 p.m. ; 

 whereas the lowest rate of the upper currents is about 

 midday. 



The diurnal variation of height is remarkable, for they 

 find at Upsala that the mean height of all varieties of 

 clouds rises in the course of the day, and is higher 

 between 6 and 8 in the evening than either in the early 

 morning or at midday. 



Such are the principal results that have been obtained 

 at Upsala, and no doubt they surpass any previous work 

 that has been done on the subject. But whenever we see 

 good results it is worth while to pause a moment to con- 

 sider the conditions under which the work has been deve- 

 loped, and the nature and nurture of the men by whom the 

 research has been conducted. Scientific research is a 

 delicate plant, that is easily nipped in the bud ; but which, 

 under certain surroundings and in a suitable moral atmo- 

 sphere develops a vigorous growth. 



The Meteorological Institute of Upsala is an offshoot 

 of the Astronomical Observatory of the University ; and 

 a University, if properly directed, can develop research 

 which promises no immediate reward in a manner that 

 no other body can approach. 



If you want any quantity of a particular kind of calcu- 

 lation, or to carry on the routine of any existing work in 

 an Observatory, it is easy to go into the labour market 

 and engage a sufficient number of accurate computers 

 either by time or piece-work, or to find an assistant who 

 will make observations with the regularity of clockwork. 

 But original research requires not only special natural 

 aptitudes and enthusiasm to begin with, but even then 

 will not flourish unless developed by encouragement, and 

 the identification of the worker with his work. It is 

 rarely, except in Universities, that men can be found for 

 the highest original research. For there only are young 

 students encouraged to come forward and interest them- 

 selves in any work for which they seem to have special 

 aptitude. 



Now, this is the history of the Upsala work. Prof. 

 Hildebrandsson was attached as a young man to the 

 meteorological department of the Astronomical Observa- 

 tory, and when the study of stars and weather were 

 separated, he obtained the second post in the new 

 Meteorological Institute. From this his great abilities 

 soon raised him to the directorship, which he now holds 

 with so much credit to the University. M. Ekholm, a 

 much younger man, has been brought up in the same 

 manner. First as a student he showed such aptitudes 

 for the work as to be engaged as assistant ; and now, as 

 the actual observation and reduction of the cloud-work is 

 done by him and M. Hagstrom, the results are published 



under their names, so that they are thoroughly identified 

 with the work. 



Upsala is the centre of the intellectual life of Sweden, 

 and there, rather than at Stockholm, could men be found 

 to carry out original research. It redounds to the credit 

 of the University that it has so steadily supported Prof. 

 Hildebrandsson, and that he in his turn has utilized the 

 social and educational system by which he is surrounded 

 to bring up assistants who can co-operate with him in a 

 great work that brings credit both to himself, to them- 

 selves, and to the Institute which they all represent 



Ralph Abercromby. 



A NEW COSMOGONY} 



I. 



nr*HE volume before us is composed of a series of 

 *- essays, first published in the Catholic periodical, 

 Natur und Offenbarung, in 1885-86. By far the greater 

 part of it is, nevertheless, of a purely scientific character. 

 The opening chapter alone enters upon theological con- 

 siderations, which we cannot here pretend to discuss, 

 recommending merely, in passing, the broad and wise 

 doctrines it contains to the notice of those well-meaning 

 persons who apprehend danger to creeds from specula- 

 tions as to origins. 



That of our planetary system is very actively in debate 

 just now. The nebular hypothesis, as fashioned by 

 Laplace, no longer fits in with all the known facts. There 

 are so many of them that it would be surprising if it did, 

 since the outside of its claim was to the plausible repre- 

 sentation of possible truth. It had a part to play in the 

 history of science, which it played with eminent success. 

 This was to show that thought, safeguarded by right 

 reason, might be trusted to run backward towards the 

 beginnings of things — that, without visible discontinuity 

 or breach of known laws, the present fair scheme of 

 creation might have emerged from the brooding darkness 

 of chaos, along paths not wholly inaccessible to human 

 discursive faculties. 



But now the reiterated blows of objectors may fairly be 

 said to have shattered the symmetrical mould in which 

 Laplace cast his ideas. What remains of it is summed 

 up in the statement that the solar system did originate, 

 somehow, by the condensation of a primitive nebula. 

 The rest is irrevocably gone, and the field lies open for 

 ingenious theorizing. It has not been wanting. 



The newer cosmogonists are divided into two schools 

 by the more or less radical tendencies of the reforms 

 they propose. Some seek wholly to abolish, others 

 merely to renovate, the Kant-Laplace scheme. The first 

 class is best represented by M. Faye, the second by M. 

 Wolf and Dr. Braun. Dr. Braun is, however, a more 

 thorough-going renovator than M. Wolf. The edifice, as 

 " restored " by him, shows, indeed, little trace of its 

 original aspect. Scarcely the invisible foundations are 

 the same ; the superstructure is unrecognizable. We will 

 endeavour to sketch its main features. 



In widening the nebular hypothesis to embrace the 

 whole sidereal world, our author demands as little as 

 possible in the way of postulates : simply a co-extensive 

 nebula, structureless, motionless, tenuous, its particles 

 endowed with gravity and atomic repulsion. Such a 

 nebula, if perfectly homogeneous, should give birth to 

 one portentous, solitary sun. But, in point of fact, it 

 would possess innumerable, almost imperceptible, local 

 irregularities, which, forming so many centres of attrac- 

 tion, would eventually lead to the breaking-up of the 

 nebula into a vast multitude of separate fragments. 



On one of these, the destined progenitor of the solar 



' " Ueber Cosmogonie vom Standpunkt christlicher Wissenschaft. Mit 

 einer Theorie der Sonne." Von Carl Braun, S.J. (Mi'mster : Aschendorflf, 



1887.) 



