The island of New Caledonia, from which these ores of nickel and cobalt are derived, is situated in the South Pacific Ocean, distant about 600 miles east from Queensland, Australia. The island is about 200 miles long by about 30 miles broad, and is extremely mountainous. New Caledonia belongs to the French, and it is there that they have established one of their principal penal settlements.

The magnificent researches of Andrews on the Isothermals of Carbonic Acid formed, as it were, a nucleus in a supersaturated solution, round which an immediate crystallization started, and has since been rapidly increasing.

1. It is well known that if hn denote the sum of the homogeneous products of a, b, c, … l of n dimensions, while h′n refers similarly to b, c, d, … l, then

The proof, which is very simple, may be stated thus :— We have

At the last meeting of the Society Sir W. Thomson again raised the question of (the validity of Boltzmann's Theorem, to which I had called attention two sessions ago. He expressed, at the same time, some doubts as to Clerk-Maxwell's Theorem (of which Boltzmann's is an extension); doubts, however, confined to the proof given by Maxwell, not as to the truth of the theorem itself. This theorem is the extremely important one, that in a mixture of two kinds of particles the average kinetic energy of the particles of each kind is the same. The proof, as given in the Philosophical Magazine for 1860, is so very condensed as rather to surprise the reader by the extraordinary rapidity with which it seems to show that the final average is attained. I have, therefore, expanded it so that the nature of the approximation to the average may be clearly traced.

The most cursory examination of the wind records of the Ben Nevis Observatory shows that there is, even in fine weather, no strongly marked daily variation in their direction; nothing comparable to the land and sea breezes observed on our own coasts in summer. In order to see whether there was not some regular daily change concealed in the extremely variable winds actually observed, I reduced, by means of a traverse table, to north-south and west-east co-ordinates each observation during the summer months (June, July, August) of 1884 and 1885, taking account of the velocity of the wind as well as of its direction, so as to get the actual mean air motion at each hour of the day.

In my previous communications to the Society on this subject some different forms of thermometer screens are described, and the results are given of a number of trials made with them during trying conditions of weather. The result of these tests showed that all the screens gave readings a little too high when there was much radiation, and that the thermometer in the fan apparatus also indicated too high a temperature, the readings of a fine-bulbed thermometer in a polished silver case being taken as our standard of temperature in these trials. The reasons are given for the thermometer in the draught screens indicating too high temperature, and the ineffectual attempts made at the time to check these errors are described.

The instruments which we have called chromomictors, have been designed for the purpose of mixing lights of different colours for experiments in physiological optics. There are already a considerable number of instruments for this purpose, but none of them are perfectly satisfactory. We shall here describe one or two new forms of apparatus which have been recently experimented with, and though they may not be suitable for many colour experiments, yet they seem to possess some advantages over several of the instruments now in use.

Two instantaneous Photographs—one of the explosion of Hellgate. and the other of the “Genista” yacht—were exhibited by tht Astronomer-Royal for Scotland. The thanks of the Society were accorded to the Astronomer-Eoyal.

The simplest form of the interlacing surfaces as spread upon a plane is illustrated in fig. 1. It will be seen that we have here three sheets, differently shaded so as to distinguish them to the eye, but otherwise quite similar.

In my paper of January 18th (anté, p 537) I had assumed all directions of the line of centres at impact to be equally probable. The introduction of the true condition affects the average value of

by a numerical factor only; so that the proof of Maxwell's Theorem remains valid. The expressions for the separate average values of u2 and of uv, however, are altered more profoundly.