PaaS at | ce 
| NATURE — 
94 
which we sum up the light—do not localise the light, but throw 
it together —it does not matter whether your clock goes well or 
not, you are certain to have a result worthy of credit. But if 
you employ such an instrument as Prof. Respighi employed, 
and abolish the slit altogether, the weight of any observations 
made with such conditions is very great. 
Captain Maclear, who was observing with me at Bekul, has 
undoubtedly shown that when the light of our atmosphere is 
cut off by the interposition of the dark moon, we see very many 
more bright lines than we do when this is not the case, the lines 
being of unequal height. 
Mr. Pringle, also at Bekul, showed that, at the end of to- 
tality, many lines flashed into one of these instruments, carried 
under these difficult conditions. : 
Captain Fyers, the Surveyor-General of Ceylon, observing 
with a spectroscope of the second kind, saw something like a 
reversal of all the lines at the beginning, but nothing of the kind 
at the end. rahe 
Mr. Fergusson, observing with a similar instrument, saw re- 
versal neither at the beginning nor the end. 
Mr. Moseley, whose observations are of great weight, says 
that at the beginning of the eclipse he did not see this reversal 
of lines. Whether it was visible at the end he could not 
_tell, because at the close the slit had travelled off the edge of the 
moon. : 
Prof. Respighi, using no slit whatever, and being under the 
best conditions for seeing the reversal of the lines, certainly did 
not see it at the beginning, but he considers he saw it at the end, 
though about this he is doubtful. : 
From the foregoing general statement of the observations made 
on the eclipse of last year, it will be seen that knowledge has 
been very greatly advanced, and that most important data have 
been obtained to aid in the discussion of former observations. 
Further, many of the questions raised by the recent observations 
make it imperatively necessary that future eclipses should be 
carefully observed, as periodic changes in the corona may then 
possibly be found to occur. In these observations the instru- 
ments above described should be considered normal, and they 
should be added to as much as possible. 
I had intended, if time had permitted me, to point out how 
mach better we are prepared for the observation of an eclipse 
now than we were when we went to India, and how a system of 
photograph record should be introduced into the spectroscopic 
and polariscopic work ; but time will not allow me to do more 
than suggest this interesting topic. I am anxious, however, that 
you should allow me one minute more to say how very grateful 
we feel for the assistance rendered by all we met, to which as- 
sistance so much of our success must be ascribed. I wish thus 
publicly to express the extreme gratitude of every one of our Ex- 
pedition to the authorities in India and in Ceylon for the assist- 
ance we received from them, and our sorrow that Admiral 
Cockburn, a warm and well-known friend to Science, who 
placed his flagship at the disposal of the expedition, and the 
Viceroy, whose influence in our favour was felt in every region 
of India whither our parties went, and to whom we gave up our 
ship, are now, alas ! beyond the expression of our thanks. We 
are also anxious to express our obligations to the directors and 
officers of the Peninsular and Oriental Company for the magnifi- 
cent way in which they aided us. If they had not assisted us as 
they did, Science would have gained very much less than she 
has done from the observations of the last eclipse. . 
SCIENTIFIC SERIALS 
Tur Fournal of the Quekett Microscopical Club for October 
1872, contains but three papers, of which the first is a short one 
by Dr. Guy, F.R.S., on the “ Hand Illuminator Microscope,” 
which is followed by a more elaborate communication of con- 
siderable length, by Mr. M. C. Cooke, on *‘ Old Nettle Stems 
and their Micro-fungi,” in which twenty-seven species of fungi 
are enumerated and described which develop themselves on the 
old stems of the common nettle,—C. H. Peck, of Albany, U.S., 
communicates an article on the disease of plum and cherry 
trees in the United States known as ‘‘black knot,” and his 
observations on the structure and growth of the Sfheria 
moaybosa (Schweinitz) which accompanies, or causes, these 
gouty excrescences. The record of the proceedings of the club 
completes the contents of the present number. 
Bulletin de V Académie Royale de Belgique, No. 7. This num- 
ber contains a paper, by M. P. J. Van Beneden, on the fossil 
whales of Antwerp, in which he describes several new 
among others, one (named Cetotherium) characterised chiefly 
the articular condyle on the inferior maxillary, and forming 
transition-type between the Balzenoptera and the Cetodo: 
Four species of Cetotherium are described. G,. Dewalque 
a description, with plate, of a new fossil sponge, met with ii 
Eifel system ; a species of the Astraospongium of Roemer, 
named from the six-rayed star fornts composing it. A new mi 
of estimating the advantage of binocular vision over monoculé 
as regards the brightness or clearness of objects, is proposed t 
H. Valerius. He employs Foucault’s photometer, which co 
sists of a long box, having a glass disc fixed in one end of it, z 
a pasteboard diaphragm in the direction of the axis of the bo 
moveable to or from the disc with screws. Lights are placed 
either side of the diaphragm, which thus forms shadows on 
disc, andthe diaphragm is so adjusted that the shadow from e 
light occupies half of the disc. The lights having been so 
justed that the disc seems uniformly lighted, their relative inte 
sities are as the squares of the distances separating them from t 
disc. M. Valerius uses, for his purpose, a prismatic tub 
through which he observes the disc of the photometer. It coi 
tains a vertical screen which conceals one-half of the dise fro 
one of the eyez. Suppose the disc to be receiving equ 
quantities of light from the two sources, the observer, on lookit 
through the tube, finds that the half-dise seen with only one e; 
appears less illuminated than the other. The equality is restor 
by moving one of the lights, and the distance of the motion 
measured.—This paper is followed by one on formule 
Ballistics, by J. M. De Tilly.—In the literature departm 
Baron Kervyn de Lettenhove gives an interesting account 
certain documents which he examined at Hatfield House, beari 
on the later history of Mary Queen of Scots. He discusses 
celebrated casket letters, two of which are preserved at Hatfiel 
and are considered by him to be translations from the Scotch text, 
The letters are given in lithograph.—E. Varenbergh communi- 
cates an account of a journey made by three Flemish gentlem 
to Nuremberg in the thirteenth century; an exact statem 
being made of the expenses incurred in travelling. One or t 
minor articles complete the number. an 
Poggendorff's Annalen der Physik und Chemie.—No. 7 (1872) 
commences with a paper of careful research, by H. Knoblauch, 
on the passage of heat-rays through inclined diatherma1 
plates. The rays, polarised by a Nicol’s prism, were caused 
pass horizontally to the plate, which was moveable about a 
tical axis, and, passing through it, affected a thermopile. T 
things determine the passage of radiant heat through inelin 
plates—the nature of the ray’s polarisation, and the absorpti 
of the substance composing the plate. These two influences 
fully investigated and their effects described.—A continu 
account, by Hagenbach, of researches on Fluorescence is follow: 
by a somewhat mathematical paper by Ketteler (also a co 
tinuation), on the influence of astronomical motion on optical 
phenomena. Dr. Stoletow discusses at some length the ‘* Func- 
tion of Magnetisation” of soft iron, and a description is give: 
G. Vom Rath, of the meteoric stones which fell at Ibbenbiin 
in 1870. W. Beetz, in a short note, contests the assertion 
Zollner, that an electric current is generated in the flowing 
water, pointing out that, in the experiments made, the ele 
phenomena probably arose from the actual formation of a volt: 
element consisting of two different metals (of tap and pipe), a 
the water, so that the same thing might be observed though t 
water was at rest. Zollner’s theory of terrestrial magneti 
connects itself with the observation in question, as he 
the flowing liquid masses in the earth’s interior generate electric 
currents by their motion, This number contains, in addition, 
two contributions on the structure of hailstones, and one or two 
other short notes. 
No. 8 contains the concluding part of Herr Hagenb 
researches on Fluorescence. His experiments, made wit 
great variety of substances, confirm Stokes’s laws. He co 
siders that all the rays are capable of exciting fluorescence. T 
maxima of the fluorescence varied from 7 (in chlorophy! 
downwards. The spectrum of the fluorescent light vari 
also for different substances, but no necessary connecti 
was apparent between the ‘‘intermittence” in : 
fluorescence of the ordinary spectrum, and that in th 
fluorescence spectrum. Change of solvent often displaced 
the maxima. He points out the similarity between ‘phospho- 
rescence and fluorescence, and thinks these are phenomena dif 
ing not in kind, but only in degree.—In the next pay 
