March i8, 1909] 



NA TURF 



States to 1783, in the British Museum, in Minor London 

 Archives, and in the Libraries of Oxford and Cambridge." 

 This large volume runs to 500 pages, and has been pre- 

 pared by Prof. C. M. Andrews, of the Johns Hopkins Uni- 

 versity, and Miss Frances G. Davenport, of the Carnegie 

 Institution. The volume is but one of a series, of which 

 two volumes have appeared previously, in which the 

 Carnegie Institution proposes to present inventories guiding 

 the student of American history to such manuscript 

 materials as are to be found in the archives and libraries of 

 foreign countries. 



OUR ASTRONOMICAL COLUMN. 



Stellar Evolution. — In discussions appertaining to the 

 evolution of individual masses in the cosmos, two hypo- 

 theses have received a great deal of attention, the first 

 being that of Laplace, in which masses are thrown off by 

 a condensing nebula, the second, due to Darwin, in whicli 

 iht: subdivision is due to fission caused by tidal strains. 



In No. I, vol. xxix., of the Astrophysical Journal, Prof. 

 Moulton discards the former, on the lack of evidence, and 

 discusses the probability of the latter theory. 



His results arc not favourable to the fission theory, and 

 applving them to the members of the solar system it appears 

 unlikely that the planets originated by fission from a parent- 

 mass ; similarly, he concludes that the moon and earth 

 have not originated by fission from a common parent mass. 



.Again, in reference to multiple stellar systems, the type 

 of fission discussed by Prof. Moulton appears to be ruled 

 out of court as the factor producing such systems unless 

 the parent nebula had originally well-defined nuclei. 



Prof. Moulton states that up to the present it has been 

 assumed that evolution took place from the nebulous state 

 to the stars ; he suggests that both aggregation and dis- 

 persion of matter should now be considered as possible 

 factors in cosmological evolution. 



Hale's Solar Vortices. — In an English reprint of the 

 Proceedings of the Koninklijke Akademie van Weten- 

 schappen te Amsterdam, at the meeting held on January 30, 

 we find a criticism of Hale's theory of solar vortices by 

 Mr. A. Brcster, Jz., whose work on periodicity in the sun 

 and variable red stars was reviewed in N.ature for 

 February 11 (p. 431, No. 2050). 



Mr. Brcster gives reasons for doubting the existence of 

 walrrial vortices, and ascribes the varying configurations 

 of the flocculi and the spectral-line displacements to the 

 action of submerged radio-active substances from which 

 issue forth, through spot cavities, /3 and 7 rays, which, in 

 turn, cause the stationary matter of the solar atmosphere 

 to become variably luminescent. 



Comet Te-mpeLj-Swift, iqoSd. — Observations of comet 

 iqoSd were made at the .Mgiers Observatory by MM. 

 Ranibaud and Sy on nine dates between October 20 and 

 December 3, igo8. In the i2j-inch coude equatorial the 

 comet was a very feeble, nebulous object with a scarcely 

 perceptible condensation ; the coma was round, and of 

 about 2' diameter {Astronomischc Nachrichtcn, No. 4307). 



The Cape Observatory. — Mr. Hough's first report of 

 the work done at the Cape Observatory covers the two 

 years 1906 and 1907 ; owing to the change of directors, 

 consequent upon the retirement of Sir David Gill in 

 February, 1907, no report for iqo6 was issued. 



The discussion of the azimuth determinations made in 

 iqo6 showed that, although the underground azimuth marks 

 themselves were quite stable, there w^as a persistent 

 systematic difference in the results, apparently depending 

 upon the position, east or west, of the instrument ; sub- 

 sequent investigation showed that this error was due to 

 a loose tewel in the end bearing of the micrometer screw. 



.An improved system of circulating the air in the prism 

 box has greatly improved the working of the line-of-sight 

 spt ciroscope. The transit-circle, the heliometer, and the 

 cquatorials were in constant use, and brief summaries of 

 the observations made are contained in the report. 



The astrographic chart work is well advanced, the total 

 number of plates now measured being 12S5, containing 



NO. 2055, VOL. 80] 



some 700,000 star images, corresponding to nearly 300,000 

 different stars. 



During the two years under report, 496 stellar spectra, 

 mostly selected for a spectroscopic determination of the 

 solar parallax, were taken with the four-prism spectro- 

 graph attached to the Victoria (24") telescope. The radial 

 velocities of o Tauri, o Orionis, a Canis Majoris, 

 i3 Gcminorum, a Bootis, a Centauri, and o Scorpii are 

 completely reduced, and await final discussion. 



HOURS OF SLEEP FOR CHILDREN. 



THAT .a child needs proper sleep and longer hours ol 

 sleep than an adult is such a well-recognised fact 

 among common-sense people that it seems strange it should 

 still be necessary to preach it to the public. Sir James 

 Paget so long ago as 1857 pointed out the physiological 

 reasons for this necessity, in that organic processes are 

 performed with rhythm, and the habitual alternation of 

 activity and rest is an all-important factor in the realisa- 

 tion of the highest potentialities of the growing child. 

 It is during the hours of sleep that growth due to the 

 building up or anabolic side of metabolism is most in 

 evidence, and anabolism is specially necessary in children, 

 not only to repair the wear and tear of the day's activities, 

 but also because the child is growing. Eminent alienists 

 such as Sir James Crichton Browne and Dr. Clouston 

 have supported these views, and have shown the bad effects 

 want of rest has on the mental as well as the physical 

 well-being of the child. Dr. Rayner, formerly medical 

 superintendent of Hanwcll Asylum, in his evidence given 

 last year before the Royal Commission on the Care of 

 the Feeble-minded, said,' " I have had normal children 

 brought to me as defective simply as a result of 

 insomnia." 



.\ few years ago Dr. Theodore Acland brought the ques- 

 tion before the public, in a letter to the. Times, in relation 

 to the hours of sleep in boys' -^public schools. School- 

 masters, as a rule, are extremely conservative, and regard 

 early rising as a useful method of discipline. Dr. .Acland 

 was supported by Dr. Clement Dukes, and it is to be 

 hoped that their efforts have been successful in modify- 

 ing the customs at such schools, and that the means of 

 •' hardening " adopted there may be changed in favour of 

 methods which may be less harmful to the physique of 

 the boys. 



It is, however, not only in the schools and homes of 

 the better classes that the' evil prevails, and the aspect of 

 the question in relation to the poor has been specifically 

 dealt with in an article by Miss Alice Ravenhill {Child 

 Study, vol. i.. No. 4, January), which deserves wide 

 publicitv. Her investigations, illustrated by examples, 

 abundantly prove that this most important time law of 

 regular sleep is heedlessly violated, and the penalties 

 exacted are both far-reaching and heavy. The hours of 

 sleep are curtailed at both ends ; late hours of retiring are 

 the custom owing to a failure to appreciate that the child 

 is not an adult : early rising is regarded as a necessity 

 among the poor because the miserable pittances the 

 children earn before school time are held of greater value- 

 than their normal development into efficient citizens ; the 

 quality of the sleep itself is poor, for few of the mites 

 have a bed to themselves, and sleep often three, four, or 

 even five in the same bed. Miss Ravenhill gives cases 

 where a retirement at 10 p.m. or 11 p.m. at night is 

 followed by rising for milk rounds at 5.30 a.m. or 6 a.m. 

 This frequently occurs in children six years of age, and 

 the proportion of early risers increases as the children 

 reath the errand-boy age of ten or eleven. There are 

 further exceptional cases where rising for market at 3 a.m. 

 or 4 a.m. is mentioned. 



The returns for girls are not so complete as for hoys,, 

 but the evidence is abundant that the suffering is wide- 

 spread in both sexes, and the range of occupations pursued 

 is almost incredibly various. 



This is a matter which a great nation should speedily 

 rectify. The facts are collected and are indisputable , 

 action ought to be immediate ; parents must be instructed' 

 on this and other points of elementary hygiene, and legis- 

 lation on the subject appears imperative. 



