518 
NATURE 
’ 
[ March 17, 1870 
relieve any impression which might arise that the nitrogen line 
seen on the star spectrum is merely the chief nebula line crossing 
it. In the present state of the inquiry there is little doubt left 
as to the presence of hydrogen in the star ; the other lines may 
perhaps be accounted for by nitrogen alone, or by nitrogen, mag- 
nesium, and sodium. On the whole the weight of collateral 
evidence will probably be considered to be in favour of the latter 
combination, with the possibility that for sodium may have to be 
substituted the substance which produces the line in sun-pro- 
tuberance spectrum. For although there is no direct evidence as 
to identity of the line near D, if the coincidence were with the 
orange nitrogen line, it would be reasonable to expect a line in 
the star corresponding to the yellow line 1180+, yet none has 
been made out in that position ; again, the second green line has 
probably less claims for visibility than the orange or yellow lines, 
yet in the star spectrum this line is not less well seen than that 
coinciding with the chief nitrogen line; these considerations, though 
perhaps not entitled to great weight, at least lead in the direction of 
the above inference. Owing to faintness of the general spectrum no 
dark lines are made out ; one in the red is strongly suspected, and 
occasionally there is anappearance as if ofa multitude over the spec- 
trum generally, but they refuse to be seen separately and certainly. 
The spectroscope has decided that 7 in no way influences the 
configuration as now seen. Is not the presence of nitrogen and 
hydrogen in the star » a significant fact in connection with these 
changes, which appear to be nothing less than a destruction of 
nebula specially in its neighbourhood ? 
Orion has again been examined with an interesting result ; 
the spectroscope proves that in and about the trapezium nebula 
exists comparable with the bright surrounding nebula. The stars, 
sharply focused to give a linear spectrum, being threaded on the slit 
singly or in pairs, or cautiously removed out of the field, it is seen 
that the bright lines cross the trapezium with little if at all 
diminished brilliancy. The ordinary telescopic view is therefore 
an erroneous one, produced by the disturbing effect of the bright 
group. Jupiter has been examined (generally on moonlight 
nights); with this object the original Cassegrain image is too 
faint for good work, but by interposition of a suitable lens the 
image is condensed at pleasure within certain limits; with the 
light thus increased the Fraunhofer lines G,-F, 2, E, D, are 
always easily seen, C also easily on a clear night ; the lines to 
which special attention has been directed are the telluric lines 
914 and 838 (for convenience of reference the numbers in Mr. 
Huggins’s Jupiter and sky diagrams are used throughout.) 
‘These are the only lines scen with certainty between C and D. 
The identity of 914 and $38 rests partly on measures and partly 
on spark comparison, where, for the identification of 914, it is 
seen that this line is near to the air band 807 of Mr. Huggins’s 
chemical scale. The line 914 is so easily seen, that having in 
mind Mr. Huggins’s statement concerning the difficulty of dis- 
cerning it at all, originally very imperfect measures on a bad 
night, and with the apparatus imperfectly adjusted, misleading in 
the same direction, this line was at first mistaken for 882, from 
which, however, it is separated far beyond the limit of error in a 
proper state of adjustment of apparatus. 882 is not seen at 
all with Jupiter at considerable altitude. On the night of 
December 29th, however, between the hours of 12.30 and 1, 
Jupiter being low, 882 was then seen almost as conspicuous as 
914, which did not seem to have perceptibly increased in dark- 
ness by the additional absorption of the earth’s atmosphere. On 
the night of December 14th (both objects being near the 
meridian) the spectroscope was turned on Jupiter and 
the moon alternately Several times. On Jupiter 914 
and 838 were easily visible, the former (as usual) the more 
conspicuous ; on the moon no line could be certainly made 
out between C and D. 
March 16.—The following papers were read :—‘‘ On the Con- 
tact of Conics with Surfaces.” By William Spottiswoode, M.A., 
F.R.S.  ‘* Tables of the Numerical Values of the Sine-integral, 
Cosineintegral, and Exponential Integral.” By J. W. L. 
Glaisher, Trinity College, Cambridge. Communicated by Prof. 
Cayley, LL.D. ‘*‘ Researclies on Solar Physics. —No. II. The 
Positions and Areas of the Spots observed at Kew during the 
years 1865-66, also the Spotted Area ‘of the Sun’s visible disc 
from the commencement of 1832 up to May 1868.” By Warren 
De la Rue, Ph.D., F.R.S., F.R.A.S., Balfour Stewart, 
LL.D., F.R.S., F.R.A.S., Superintendent of the Kew 
Observatory, and Benjamin Loewy, F.R.A.S. ‘The paper 
commences with a continuation for the years 1864-66 of Tables 
II. and IIT. of a previous paper by the saine authors ; it then 
proceeds to a discussion of the value of the pictures of the sun 
made by Hofrath Schwabe, which had been placed at the dis- 
posal of the authors, and the result is that these pictures, when 
compared with simultaneous pictures taken by Carrington and by 
the Kew heliograph, are found to be of great trustworthiness, 
From 1832 to 1854 the pictures discussed are those of Schwabe, 
who was the only observer between these dates ; then follows the 
series taken by Carrington, and lastly the Kew series, which 
began in 1862. 
area for every fortnight, from the beginning of 1832 up to May, 
1868, and also alist of three-monthly values of the same, each 
three-monthly value being the mean of the three-fortnightly 
values which precede one of the three which follow it. These 
three-monthly values are also given for every fortnight. A plate 
is appended to the paper, in which a curve is laid down repre- 
senting the progress of solar disturbance as derived from tlie 
three-monthly values ; and another curve is derived from this by 
a single process of equalisation, representing the progress of the 
ten-yearly period. The values of the latter curve, corresponding 
to every fortnight, are also tabulated. From this Table are 
derived the following epochs of maxima and minima of the 
longer period :— 
Minimum Noy. 28, 1833. 
Maxim’ )eeeenaeenta. 08 Dec. 21, 1836; 
Minimum. Sept. 21, 1843 
DMEM Csagoqudcchn on Noy. 1, 1847. 
Minimum April 21, 1856. ~ 
NUE STEMI eco sebpoeicee Sept. 7, 1859. 
Minimum July 14, 1867. 
This exhibits a variability in the length of the whole period. 
Thus we have between Ist and 2nd minimum... .. 9°81 years. 
2nd and 3rd do. _—........ 12:5Su es 
3rd and 4th do, 7 wens 1o:sr 
Mean of all the periods ......... II ‘07 years, 
Another fact previously noted by Sir J. Herschel is brought 
to light, namely, that the time between a minimum and the next 
maximum is less than that from the maximum to the next mini- 
mum. Thus the times from the minimum to the maximum are 
for the three periods 3°06, 4°14, and 3°37, while those from the 
maximum to the minimum are 6°75, 544, and 7°44 years. In 
all the three periods there are times of secondary maxima after 
the first minimum ; and in order to exhibit this peculiarity statis- 
tics are given of the light-curve of R Sagitte and of B Lyra, 
two variable stars which present peculiarities similar to the sun. 
Finally, the results are tested to see whether they exhibit any 
trace of planetary influence; and for this purpose 54 conjunc- 
tions of Jupiter and Venus, and 90 conjunctions of Venus and 
Mercury have been made use of with the following result, ex- 
hibiting the united effect of the sun’s conjunctions, the unit of 
spotted area being one millionth of the sun’s visible hemi- 
sphere. 
Excess or Deficiency. 
Angular separation, Jupiter and Venus. Venus and Mercury. 
oto 30 + 1675 
30 to 60 son) = Hite) 
60 to go. tee = OOS 
go to 120 soa) = 2355 
120 to 150 nog SS EUS 
150 to 180... +. = 1604 
180 to 210... so = | AST 
210 to 240 ot BAF 
240 to 270... + 431 
270 to 300... + 228 
300 to 330... . + 1318 
330to Oo + 2283 
Chemical Society, March 3.—Prof. Williamson in the chair, 
“On Refraction Equivalents.” By Dr. Gladstone. Three distinct 
lines of research had led up to the discovery of these equivalents. 
The first was the influence of temperature on the refraction of 
light by liquids ; the second, the refraction of mixtures or com- 
binations as compared with that of their constituents ; and the 
third, the refractive indices of different members of homologous 
series of organic compounds. As to the first of these it was found 
by the joint labours of Dr. Gladstone and the Rey. Pelham Dale, 
that the refraction and the dispersion decrease as the temperature 
rises. Further examination showed a close relation between the 
change cf density and the change of the refractive index minus 
unity, which the investigators termed the ‘‘ refractive energy,” 
A list is given of nine values of the sun’s spotted — 
2» ip) pe AO PEN 
tients. ce 
«im 
ee 
