tc betel ae 
% 
240 
will take place in September, 1884, at Magdeburg. 
Dr. Neumayer is president. 
The aim of the society is to pay attention to the 
science of meteorology, as well as its relations to prac- 
tical life. As a means of accomplishing this, 1°, 
meetings of the society and its branches will be es- 
tablished ; 2°, a journal of meteorology will be issued; 
38°, meteorological investigations will be aided, partly 
directly, and partly through its branches; 4°, lectures 
and other measures will be introduced for the distri- 
bution of meteorological knowledge in wider circles. 
The members are to be honorary, foundation, ordi- 
nary, and corresponding. ‘The yearly assessment for 
ordinary members is ten marks ($2.50). 
From private letters we are informed that the first 
number of the journal will be issued in a couple of 
months. It might seem at first as though this new 
journal would interfere with the work of that ex- 
cellent journal, the Oesterreichische Zeitschrift fiir 
meteorologie ; but we believe that the editors of the 
journals will enter into such relations with each 
other that the two journals shall be supplementary 
the one to the other. It may be expected that this 
new journal will occupy as important a place as the 
Austrian, and therefore it ought to find its way into 
the hands of all those who wish to keep informed of 
the progress of this science. The Deutsche seewarte 
at Hamburg will naturally be the chief seat of work 
in connection with the issue of this journal. The 
treasurer of the society is Mr. Ernst Bopp, Konig- 
strasse, No. 6 ", Hamburg. 
— The M. P. club, a club of mathematicians and 
physicists living in Boston and vicinity, which meets 
once a month for the discussion of vexed questions 
in their departments, has issued the following list of 
subjects for discussion : — 
1. Given a solid body in which the moments of in- 
ertia about four axes passing through one point are 
equal, does it follow that the moments of inertia 
about all axes, through the same point, are the same? 
2. Are there any general methods for determining 
the form of a function when certain special values 
are known, or when certain conditions are given? 
For example: (a) To find F(a, y, 2), given F(z, z, z) 
=0,and F(z,y,z) =1. One solution is F(x, oe z)= 
cy 
eae what others are there ? )p= r(% 4 as) 
: ue du dp oe ie 
t= 8 gal: Sven a. >» — 9, also given, 
du 
U 
that, when me and dy ae interchanged, then p and ¢ 
are interchanged, to find F and F. 3. “Is it, there- 
fore, an essential condition of equilibrium that 
p(Xdx + Ydy + Zdz) should be a perfect 
differential of some function?’? (W. H. Besant’s 
‘Hydromechanics,’ p. 13.) ‘‘In this case of com- 
pressibility, wdy — vdz is not the differential of any 
function; so that the function F does not exist, 
although, of course, stream lines exist’? (Minchin’s 
‘Kinematics,’ p. 152). Such passages as these sug- 
gest the inquiry, ‘‘ How are we to interpret physically 
the fact that a given differential is not an exact differ- 
SCIENCE. 
ential ?’’ (see Clausius’ ‘ Mechanische wiirmetheorie,’ 
4. The graphical treatment of algebraic prob- 
p- 4.) 
lems (see Vose’s little book on the subject, published — 
by Van Nostrand). 5. Graphical statics. 6. Anhar- 
monic ratios; suggestions of new nomenclature. 
7. Koenig’s researches on beats and beat tones. 8. 
Euclid’s doctrine of proportion. 9. Multiple algebra. 
10. The comparison of Grassmann’s theory of exten- 
sion and Hamilton’s quaternions. 11. Imaginaries 
in quaternions. 12. Weierstrasse’s investigations in 
analytics and geometry. 13. The precise nature of 
the ancient problem of the quadrature of the circle. 
14. The twelfth axiom of Euclid. 15. The bearing 
of the modern conception of non-Euclidean space on 
our theory of the foundation and certainty of geo- 
metric truth. 16. The true relation of hyper-space 
analytics to questions of actual existence. 17. Rie- 
mann’s surfaces. 18. The meaning of an infinitely 
distant point on a straight line. 19. = does not 
equala —a. 20. Cayley’s exposition of the logical 
structure of plane geometry (‘ Encycl. Brit.,’ 9th ed.). 
21. The synthetical (as opposed to analytical) char- 
acter of all judgment and proof that is strictly 
mathematical. 22. The development of algebra from 
first principles as the science of pure time. 238. The 
calculus of logic. 24. The writings of Francois Viéte. 
25. Comparative merits of the method of limits and 
method of infinitesimals in elementary methods. 
26. The same in the exposition of the higher calculus 
(with especial reference to Johnson and Rice’s new 
‘Method of rates’). 27. Is gravitation a truth em- 
pirical, or a priori ? and the limits of Newton’s law of 
rate in gravity. 28. The principle of least resistance. 
29. What exactly is meant by the correlation of 
forces, and what is its bearing on the conservation 
of energy ? 30. The dissipation of energy. Its mean- 
ing and bearing on the stability of the universe. 31. 
Recent researches upon the atomic theory and upon 
the resolvability of the elements. 32. What consti- 
tutes the chief resistance in the case of a bec y moving 
through the water? 33. What is the form of least 
resistance for a row-boat? What for a-sail-boat? 
What for a steamer? 34, Cause of capillary ascen- 
sions and depressions. 35. The means whereby water 
is able to penetrate capillary tubes against a superior 
pressure of a gas (see Daubrée’s ‘ Etudes synthétiques 
de géologie expérimental,’ Paris, 1879). 36. Micro- 
scopic action. 387. The diathermancy of ice from 
the point of view of James Croll’s theory of glacial 
motion. 38. Direction of electric currents in diamag- 
netic bodies, e.g., bismuth. 39. Underground tele- 
phone circuits. 40. Elasticity and permanent set. 
41. Diffraction gratings, plane and curved. 42. A 
short discussion (not too technical) on some of the 
instruments of research, such as the bolometer and 
the inductive balance. 43. Recent researches on the 
distance of the sun. 44. The origin of meteorites: 
are they volcanic ejections? 45. The aurora borealis, 
zodiacal light, ete. 
pressed, is it possible to get a compression curve 
concave downwards (abscissae representing volumes, ~ 
and ordinates pressures), and, if so, when ? 
46. If steam be enclosed in as 
cylinder open on the outside to the air, and com- — 
