Report of the ... Meeting of the British Association for the Advancement of Science

The cell thus set up may be mounted in any desirable manner. It is convenient to arrange the mounting so that the cell may be immersed in a water bath up to the level of, say, the upper surface of the cork. Its temperature can then be determined more accurately than is possible when the cell is in air.

Interim Report of the Committee, consisting of Professor CAYLEY, Professor SYLVESTER, Mr. A. R. FORSYTH, and Professor A. LODGE (Secretary), appointed for the purpose of carrying on the Tables connected with the Pellian Equation from the point where the work was left by Degen in 1817.

A LARGE part but not the whole of the work has been completed, but the Committee hope to have it completed in time for next year's meeting of the Association.

101. of the grant of 151. has been expended.

Seventh Report of the Committee, consisting of Sir G. G. STOKES (Chairman), Professor SCHUSTER, Mr. G. JOHNSTONE STONEY, Sir H. E. ROSCOE, Captain ABNEY, Mr. WHIPPLE, Professor MCLEOD, and Mr. G. J. SYMONS (Secretary), appointed for the purpose of considering the best methods of recording the direct Intensity of Solar Radiation.

YOUR Committee have to report that, after considerable search, Professor Schuster found the thermometers constructed for Professor Balfour Stewart for use with the apparatus designed by and constructed for him, and that the apparatus and a mass of correspondence relating thereto had been placed in Professor McLeod's hands. He reports that he has tested all the thermometers, and made observations with the instrument when opportunity has offered. He has found it desirable to provide a screen to prevent the action of the sun on the outside of the instrument affecting too much, or too unequally, the reading of the internal thermometers. It was always contemplated that the action of the sun on the case of the instrument would affect the embedded thermometers; but as care was taken that the central thermometer should be prompt in responding to changes of temperature, while the embedded thermometers, in consequence of the way in which they were protected, should change but slowly, it was expected that the difference between the temperatures marked by the central thermometer and by the embedded thermometer respectively would be sensibly proportional to the intensity of solar radiation, notwithstanding the changes of temperature of the outer case. This anticipation, the correctness of which is of vital importance to the success of the instrument, has not, however, as yet been tested experimentally, and the trials would require to be made under specially favourable atmospheric conditions. The Committee hope to report definitely in the course of another year as to the utility of the apparatus and desire reappointment without any grant.

Report of the Committee, consisting of Sir H. E. Roscoe, Mr. J. N. LOCKYER, Professors DEWAR, WOLCOTT GIBBS, LIVEING, SCHUSTER, and W. N. HARTLEY, Captain ABNEY, and Dr. MARSHALL WATTS (Secretary), appointed to prepare a new series of Wave-length Tables of the Spectra of the Elements and Compounds.

IRON (ARC SPECTRUM).1

(† denotes one of Rowland's 'normal' lines, or one of Müller and Kempf '300' lines, as the case may be).