604 
THE SEARCH FOR A, PLANET BEYOND NEPTUNE.—Herr 
T. Grigull, of Miinster, Germany, describes in the October 
number of the Bzz/letin de la Société Astronomigue de France his 
new contribution to the research which has for its object the 
discovery of another planet, beyond the orbit of Neptune. 
In a previous paper (Au//etin, January, 1902, p. 31), Herr 
Grigull explained the hypothesis on which his calculations are 
based, and the elements of the hypothetical planet as deduced 
from the observations of the aphelia of three comets. In the 
present contribution, the elements given below have been calcu- 
lated from the observed aphelia of twenty comets which appeared, 
and were observed and recorded, between the years 1490 and 
1898. After giving due weight to the various cometary observa- 
tions, the author has calculated these elements for the possibly 
existing planet :-— 
Epoch 1902. 
A = 357.54 + 1°'867 
Dist. from sun = 50°61 R. 
Time of revolution = 360 years. 
Qy="oon (ers). 
or. 
A New MInNor PLANnet.—In No. 3819 of the Astronomische 
Nachrichten, Prof. Max Wolf announces, along with other 
minor planetary observations, the discovery of another new 
minor planet, 1902 T. 
Comet 1902 6.—A number of observations of this comet 
have been made. : 
A photograph taken on September 27 by Prof. Kononowitsch, 
Odessa, with three hours’ exposure, shows a straight double tail 
extending in a southerly direction to a distance of 3°. 
Prof. Nijland has published, in the Astronomische Nachrichten 
(No. 3817), a further ephemeris, from which the following extract 
is taken :— 
1902. pape: a. app. 6. Brightness. 
. m. Ss, ° ‘ 
Oct. 16 18 16 24 +16 30°5 
17 9 55 14 9'I 
18 AN II 589 1370 
19 17 58 52 9 59°! 
20 54 6 8 89 
21 49 43 6 27°3 
ENS 45 41 4 53°06 se 10'°9 
23 17 41 56 +3 26°9 
The brightness of the comet on September]6 is taken as unity, 
and it was then estimated at 7°5m. 
THE BRITISH ASSOCIATION AT BELFAST. 
SECTION A. 
SUBSECTION OF ASTRONOMY AND COSMICAL PHYSICS, 
OPENING ADDRESS BY ARTHUR SCHUSTER, F.R.S., 
F.R.A.S., CHAIRMAN OF SUBSECTION. 
Our proceedings to-day constitute an innovation and require 
a few words of explanation. When, a few years ago, some 
astronomers felt that our Association bestowed an insufficient 
share of attention on their subject, an easy remedy suggested 
itself in the formation of a special subsection devoted to that 
subject. Such a subsection was accordingly organised at Brad- 
ford and Glasgow, but for reasons, which are perhaps not 
altogether to be regretted, the experiment was only partially 
successful. In the meantime the work of Section A became 
heavier and heavier, and, as it seemed necessary to find some 
way of relieving its meetings, it was decided to hand over to 
the already established subsection of Astronomy other subjects, 
such as Meteorology, Terrestrial Magnetism, Seismology, and, 
in fact, anything that the majority of physicists is only too glad 
to ignore, 
When the Council of the British Association asked me to act 
as President of such an enlarged subsection, I was very doubtful 
whether I ought to accept the honour. In the first place, I felt 
incompetent, owing to my almost complete ignorance of most 
branches of astronomy, and in the second place I do not ap- 
prove of the formation of subsections dealing with important 
branches of Physics. If I eventually consented, it was partly 
because I lacked the strength of mind to refuse an honour of 
NO. 1720, VOL. 66] 
NATURE 
[OcTOBER 16, 1902 
this kind, but partly because I was glad to have an opportunity 
of raising the whole question of the organisation of our meet- 
ings. The ground for such a discussion has, however, to a 
great extent disappeared, because, when the Organising Com- 
mittee of Section A met in the spring, there appeared amongst 
those present a sudden revival of interest in the subjects 
assigned to the subsection and it was decided that the main 
section should not meet at all to-day so asto allow its members 
to help us in our discussions. The parent section has, there- 
fore, voluntarily submitted itself to absorption by its neglected 
offspring, which now has to show that Cosmical Physics obeys 
the laws of Terrestrial Physics and that good absorbers are also 
good radiators. 
Gratifying as this reunion must be to us, it fails to realise one 
of the original objects for which we have been called into 
existence, because instead of lightening your work it has added 
to it by imposing upon you the burden of having to listen toa 
second Presidential Address. I will try to make this additionab 
burden as light as possible by concentrating my general remarks 
into a few sentences and then introducing the business of the, 
section by means of a contribution to its scientific work, which 
I otherwise should have made in the ordinary course of the 
meeting. 
To make our meeting as fruitful as possible, we should make 
the fullest use of the opportunities it gives us of personal con- 
tact and interchange of ideas. This is not accomplished by 
dividing into separate camps as soon as we have come together, 
but rather by finding some common ground for our debates. We 
should not try to minister to the separate needs of the specialist 
in electricity, or in meteorology or in astronomy, but should im- 
press upon each of these specialists that they must bring before 
us the results of their investigations in so far as they bear on the 
more general questions in which we all are, or ought to be, 
interested. If it is necessary to lighten the work of the section 
this should be done by excluding all papers which are of interest 
only to specialists, or by establishing subsections for such papers. 
Let us divide—if divide we must—according to the character of the 
contribution, rather than according to the subject it happens to: 
deal with. The difficult and, perhaps, unpopular censorship. 
which such a course would involve would probably be temporary 
only, as the character of the papers which are desired for the 
main section would soon become known, and the increased 
attraction and usefulness of our discussions would, I am con- 
vinced, in a few years compensate for the initial trouble. We 
all require, occasionally, to be reminded that the detail work 
which is necessary, and on which most of us are engaged, is 
only of importance or interest if it helps us forward towards 
the solution of the great problems of Nature. ; 
Addressing myself more particularly to Astronomers, I should 
like to say that we shall always welcome them as members of 
Section A, and that the benefit we shall derive from their con- 
tributions will be great in proportion as they will consider 
themselves to be citizens of the general empire of that section 
rather than inhabitants of an independently governed State. 
There is one minor reform, or perhaps [ ought to call it a 
protest against one of the traditions of the Association, which I 
feel called upon to urge on you. Discussion is our principal 
aim, and we are always trying to find suitable subjects for dis- 
cussion ; yet we are prevented by the rules of the Association 
from discussing the Presidential address and the reports of Com- 
mittees. Those who framed such a rule must have had some 
unfortunate idea that the dignity of the chair might be en- 
dangered if some criticism happened to be expressed in the 
discussion of the Chairman’s address, or that the value of the 
report of a Committee might be endangered by some adverse 
comment coming from outside. But it seems to me that a 
scientific society or association, and especially one framed on a 
democratic constitution, ought not to take such a narrow and 
unscientific view. I can remember several Presidential addresses 
which might, and probably would, have given rise to most in- 
structive debates had the rule not existed. Reports of Com- 
mittees if not suitable for discussion should not be read at all ;, 
but if read they should be open to discussion. 
I hope that to-day you will not feel yourself bound by ancient 
custom, but in order that, at any rate, the more scientific portion. 
of my contribution to our proceedings should not be stained by 
the suspicion of immaculate conception, I will now ask the duly- 
constituted President of our section to take his proper place. 
The question I wish to bring to your notice to-day is an old 
one: if two events happen simultaneously or one follows the 
