5:0 
NATURE 
[April 27, 1871 

the corona is cosmical, solar, and the denser part of the zodiacal 
light,* might expect the latter rather to show the corona’s green 
line, viz., 1474 (Kirchhoff). 
This, however, the zodiacal light, according to M. Angstrom, 
does not. Is the zodiacal light then telluric and auroral, not 
solar and coronal? The measurement of the A/ace of its green 
line should settle at once this most important and extensive 
physical question; and if the line be at any time visible at all, 
the large spectral distance between 1249 and 1474 (Kirchhofi’s 
scale) would be sensible in the simplest apparatus. Yet, in these 
high latitudes the zodiacal light is always so extremely faint, so 
frequently altogether masked by auroral glows, and as yet, for 
its spectrum, depending, so far as I know, on only one observer, 
and he residing in quite an aurora-ridden part of the world, that 
it would seem to be a perfectly fair question to ask, ‘‘ if any one 
else, besides the distinguished Natural Philosopher at Upsala, 
has observed the spectrum of the zodiacal light ; and if so, how 
and where ?” 
C. Prazzt SMYTH 
Royal Terrace, Edinburgh, April 14 
* [We venture to doubt this. —Ep. ] 

Aurora by Daylight 
T sEE that more than one of your correspondents in December 
numbers dispute the possibility of an aurora being seen by day- 
light. It doubtless is a rare occurrence, but two cases of the 
kind have come under my notice. 
In December last my son saw what he took to be an aurora 
a little before sunset. He was at the time about three miles 
from home, and he had it constantly before him during his walk 
homewards, and saw it more and more developed as the darkness 
increased, so that there can be no doubt of the appearance be- 
fore sunset being identical with what proved to be, as the night 
advanced, one of the most brilliant displays which we have had 
during a year very prolific in auroras. He states that after the 
sun had set, but whilst it was still quite light, the bright rose 
colour which distinguished that aurora was distinctly visible. 
The streamers that night proceeded from all parts of the heavens, 
meeting almost in the zenith, but what is very unusual, they 
were very much brighter in the east and south-east than in 
any other direction, which is probably the reason why they 
were so clearly visible whilst the sun was in the opposite 
quarter. 
The other case came under my own observation in September 
1849. Immediately after the sun had set, with a perfectly clear sky, 
I noticed three slightly diverging beams of light on the western 
horizon. One might almost have taken them for those beams 
from a setting sun which one sees much more often in pictures 
than in nature, had it not been that they did not emanate exactly 
from the spot where the sun had set, that they had an evident 
motion to the southward, and that two of them extended to the 
zenith, and finally down to the eastern horizon. It proved to be 
the most symmetrical auroral arch I ever saw. The perfect 
horizon I had to the west, and the straightness of its well- 
defined edges, joined to the facility which the double arch 
afforded of measuring the distance between the middle of each, 
immediately struck me as affording an opportunity of calcula- 
ting its elevation above the earth, upon the supposition that the 
tapering away towards the horizon was the effect of perspective 
alone. I took steps therefore to measure the apparent width in the 
horizon and overhead, and also its rate of motion to the southward 
in both places, and by both methods the result was about 8 to 1. 
From these data, upon the assumption that it was a double ring 
everywhere equidistant from the earth’s surface, and moving 
parallel to itself, I calculated the elevation, which came out 97 
miles, and its rate of motion to the southward 656 miles per 
hour, the auroral meridian being N. 13° 15’E., and the incli- 
nation of the plane of the arch to my horizon 94° 55’. These 
figures, whatever reliance can be placed on them, have nothing 
to do with the present question further than to show how bright 
the object must have been thus to attract my attention, and 
that, although the sun had set, there was still daylight enough 
for me to see the second hand of my watch, and to note the ob- 
jects on an horizon some three or four miles distant, by which I 
measured the progress of the base of the arch, and the bearings 
of which I took thenext day. Before it became really dark, the 
arch had become irregular, and detached streamers showed them- 
selves in the usual form, 
Ottawa Joun LANGTON 


UNIVERSITY INTELLIGENCE 
OXFORD 
UEEN’S CoLLEGE.—Mr. Charles Thomas Blan- 
chard of Clifton College, was elected to a Scholar- 
ship in Natural Science in this College on Saturday last. 
Proxime accesstt—Mr. William Percy Ashe, of Magda- 
lene College School. 
CorPUS CHRISTI COLLEGE.—There will be an Elec- 
tion to a Natural Science Fellowship in this College at 
the beginning of next Michaelmas Term. The examina- 
tion will be special y in Chemistry, and will commence on 
Monday, Oct.9 Candidates must have passed all the 
examinations required by the University for the degree of 
B A., and must not be in possession of any benefice or 
property which would disqualify for retaining a Fellow- 
ship. Candidates are requested to communicate with the 
President, either personally or by letter, at their con- 
venience, before the end of Act Term. 
Natural Science Lectures 
The following Lectures will be given in addition to 
those noticed in our number for last week :— 
Chemistry. Mr. Wyndham on the Elements of the 
Nitrogen, Boron, and Carbon groups, and their Combina- 
tions, on Thursdays and Saturdays at I1 A.M., at the 
University Museum. 
Physiology. On General Physiology, with special re- 
ference to the microscopical anatomy and physiological 
chemistry of the elementary tissues. By Mr. Chapman. 
Mondays, Wednesdays, and Fridays, at io A.M, at the 
Magdalen College Laboratory. 
Physics. On Elementary Mechanics and Hydrostatics. 
By Mr. Abbay. These lectures are free by mutual ar- 
rangement to members of these colleges at which either 
of these gentlemen is a lecturer, viz, to members of 
Merton, Magdalen, Jesus, and Wadham Colleges. 
CAMBRIDGE 
The following lectures in Natural Sciences are to be 
delivered at Trinity, St. John’s, and Sidney Sussex 
Colleges during Easter term, 1871 :— 
On Heat. (For the Natural Sciences Tripos.) By Mr, 
Trotter, Trinity College, Monday, Wednesday, Friday, at 
Io, commencing Friday, April 28. 
On Electricity and Heat. (For the Special Examination 
of the-B.A. Degree.) By Mr. Trotter, Trinity College, 
Tuesday, Thursday, Saturday, at 10, commencing Tues- 
day, April 25. Students of Colleges other than Trinity, 
e John’s and Sidney, can be admitted on payment of 
a fee. 
On Chemistry. By Mr. Main, St. John’s College. 
Tuesday, Thursday, Saturday, at 12, commencing 
Thursday, April 27. Attendance on these lectures is 
recognised by the University for the certificate required 
by medical students previous to admission for the first ex- 
amination for the Degree of M.B. 
Instruction in Practical Chemistry will also be given. 
On Geology. By Mr. Bonney, St. John’s College. 
1. Paleontology. Wednesdays and Fridays, at 9, 
commencing Friday, April 28. 
2. Lyell’s Principles of Geology. Tuesdays and Thurs- 
days, at 9, commencing Thursday, April 27. 
3. Elementary Lectures. Tuesdays and Thursdays, at 
II, commencing Thursday, April 27. Students of other 
Colleges can be admitted to these lectures on payment 
of a fee. 
On Botany (chiefly systematic and physiological.) By 
Mr, J. W. Hicks, Sidney College. Tuesday, Friday, 
Saturday, at 12, beginning Friday, April 28. 
On Physiology. The Trinity Preelector in Physiology 
(Dr. M. Foster) will probably give a short course on Em- 
bryology at the New Museums, of which notice will be 
given, 
