450 



NATURE 



\March 13, 1890 



Remarks. 

 (i) Described by Herschel as a bright extended nebula with 

 two nuclei, the north following one being very faint. In 1848, 

 Lord Rosse observed that the nebula was distinctly spiral, and 

 his drawing represents it as elliptical in shape. The nebula is 

 about 3' long and is situated about 2° south of the star \ Leonis. 

 I am not aware that any record of the spectrum has been 

 published. 



(2) A star of Group II. Duner states that the bands 2, 3, 7, 

 8 are visible, but are rather weak and not very wide. The 

 bands 4 and 5 are very delicate. The star belongs to species 

 5 of the subdivision of the group, which means that the meteor- 

 swarm of which the "star" is probably composed is somewhat 

 sparse. The bright carbon fliutings should therefore be well 

 developed. Bright lines may possibly also be present, if the 

 swarm is not too far condensed. 



(3) Konkoly and Vogel both describe the spectrum of this 

 star as a well-developed one of the solar type. The usual 

 differential observations are required. 



(4) A star of Group IV. (Vogel). The usual observations 

 of the relative thicknesses of the hydrogen and other lines are 

 required. 



(5) A star of Group VI., with a spectrum of extraordinary 

 beauty (Duner). The spectrum consists of four zones, and all 

 the bands i-io are strongly developed. Band 6 is not very 

 dark. The specific differences in stars of this group have not 

 yet been fully investigated. The principal variations so far 

 observed are: (i) the length of continuous spectrum, as indi- 

 cated by the number of zones visible ; (2) the number and 

 intensities of the secondary bands ; (3) the intensity of band 6 

 as compared with bands 9 and 10. 



Gould believes this star to be variable, his estimates of the 

 magnitude varying between 4'3 and 6"i. Birmingham's values 

 vary from 4*5 to 6 "3. The star appears to be U Hydrse, and, 

 if so, a maximum will be reached about March i8 {Observatory 

 Companion, 1890). Espin believes the period to be about 

 195 days. 



As yet, we have no information as to changes of spectrum 

 accompanying changes of magnitude in stars of this group, 



A, Fowler. 



The Solar and the Lunar Spectrum. — Prof. Langley's 

 second memoir on this subject, which was read before the 

 National Academy of Science in November 1886, has been 

 received. In a previous memoir it was demonstrated that 

 evidence of heat had been found in the invisible spectrum of the 

 sunlit side of the moon, and the experiments indicated that this 

 heat was chiefly not reflected but radiated from a surface at a 

 low temperature. The amount of heat, however, was excessively 

 minute, even when compared with the feeblest part of the solar 

 spectrum known in 1882, yet it was easily recognizable because 

 of the fact that, whereas in the typical solar spectrum heat is 

 greatest in the short wave-lengths, in the typical lunar spectrum 

 heat is greatest, in the long wave-lengths. 



In this second memoir the results of further observation of the 

 infra-red solar spectrum are given, the newly investigated region 

 being close to that which contains a large part of the lunar heat. 

 The researches considerably extend those previously made. In 

 passing from the visible part of the spectrum into the infra-red 

 region, wider regions of absorption occur. To an eye which 

 could see the whole spectrum, visible and invisible, the luminous 

 part would be, as is well known, interrupted by dark lines, the 

 lower part to 5 ^tt would appear to consist of alternate dark and 

 bright bands, and the part below 5 jw be nearly dark, but with 

 feeble " bright " bands at intervals. This appearance is shown 

 in a plate accompanying the memoir. It is noted as a curious 

 fact that the centres of several of the bands or lines are under 

 some conditions found to be shifted to a recognizable extent, 

 and hence their wave-lengths are, within certain limits, variable. 

 This apparent shift is found to be because the absorption does 

 not mcrease symmetrically with the centre of the band, but more 

 on one side than another, so as to considerably modify the 

 position of greatest absorption. 



The Corona of 1889 December 22.— The March number 

 of the Observatory contains a Woodburytype reproduction of 

 this corona taken by the late Father Perry with a short focus 

 reflector of Mr. Common's, and a note by Mr. W. H. Wesley, 

 assistant secretary of the Royal Astronomical Society, upon its 

 prominent features. Mr. Wesley finds that, as in the eclipse of 

 January I, 1889, the extension is greatest towards the equatorial 



regions, and on the longest exposed plate it can be traced tu 

 nearly a diameter from the limb. A wide rift at the north pole, 

 extending 60" or 70" along the limb, contains several fine straight 

 rays similar to the polar rays in 1878 and 1889 January i, but not so 

 numerous, regular, or distinct. The usual polar rays are scarcely 

 distinguishable at the south pole. A remarkable fact is that the 

 general mass of the corona on the eastern side is considerably 

 broader from north to south than on the western side. This was 

 also the case in 1878. Numerous prominences are seen on the 

 eastern limb, and plates taken near the end of totality show a 

 range of low prominences on the western limb. An interesting 

 feature in the plates taken with the reflector is the photographic 

 reversal of the prominences and the brighter parts of the corona. 

 In the larger exposed negatives the prominences and the corona 

 near the limb are bright instead of dark, whilst the limb itself 

 is bounded by a very definite dark line indicating a double 

 reversal. 



The Nebular Hypothesis. — Mr. Herbert Spencer con- 

 tributed an essay on Laplace's famous theory to the Westminster 

 Review for July 1858. With the assistance of Mr. Thynne 

 Lynn, a new edition of this essay has been prepared and 

 distributed amongst leading astronomers at home and abroad. 



The revised calculations bring out more strongly than ever 

 Mr. Spencer's views of the nebular hypothesis, and in particular 

 the portion referring to Mars. When the essay first appeared 

 the density of this planet was taken as o'9S, but recent and 

 more exact determinations show the value to be much too high, 

 and taking this into account the fact comes out that to agree 

 with Mr. Spencer's views Mars should have from one to four 

 satellites as it has since 1877 been known to have. 



Olbers's theory that the asteroids are fragments of an exploded 

 planet is favoured, and the genesis of the thirteen short- pei'iod 

 comets is found in the same catastrophe. It is needless to 

 say that the theory is defended in a most masterly manner, 

 although the arguments against its acceptation are overwhelming. 



Nebula, General Catalogue No. 4795. — The Journal 

 of the Liverpool Astronomical Society for December 1889, 

 which has just been issued, contains a note by Mr. W. E. 

 Jackson on this nebula, R.A. 22h, 24m., N.P.D. iii" 24'. 

 It is described in the General Catalogue as " Remarkable, 

 pretty faint, very large, extended or binuclear." Mr. Jackson 

 has carefully observed the nebula several times, and finds that 

 there are several stars involved, although no mention of them is 

 made in the Catalogue, and that there is a strong suspicion of 

 others beyond the reach of his 6 inch Grubb telescope. A sketch 

 of the appearance accompanies the note. 



A New Asteroid. — Minor planet (S^ was discovered by 

 Prof. Luther (Hamburg) on February 24. 



CAMBRIDGE ANTHROPOMETRY. 



A BOUT two years ago the results were published, in the 

 ■^*- Journal of the Anthropological Society, of the first batch 

 of measurements taken at Cambridge. These comprised rather 

 more than 1 100 cases. During the last two years a nearly equal 

 number have been obtained, and it therefore becomes important 

 to compare the results yielded by these distinct batches. 



The measurements proposed by Mr. Gallon, and adopted by 

 the Cambridge Committee, were the following : — (i) A test for 

 the eyesight. The extreme distance at which a man could read 

 "diamond type" (viz. the print employed in the little pocket 

 Common Prayer-books) was noted with each eye separately ; 

 the figures given in our tables indicate the mean of the two. It 

 may be remarked that, as this instrument would only record up 

 to 35 inches, and as about ten per cent, of the men could read 

 at this distance, it is certain that many could have seen further. 

 The arithmetical mean, therefore, though good enough for our 

 present purposes, is here less scientifically appropriate than the 

 "median." (2) A test of the muscular strength of the arms 

 when employed in an action similar to that of pulling a bow. 

 Two handles, connected at a convenient distance apart, are 

 pulled away from each other against the pressure of a spring. 

 (3) A test of the power of " squeeze " of each hand separately. 

 In this case two handles stand a short distance apart, and are 

 then pressed towards each other against the action of a spring. 

 The figures here given denote the mean of the two results. (4) 

 Measurement of the size of the head. This is taken in three 

 different directions, viz. from front to back, between the two 



