THE TELLURIC LINES OF THE SOLAR SPECTRUM-continued. Interim Report of the Committee consisting of Professor THORPE, Professor HUMMEL (Secretary), Dr. PERKIN, Professor RUSSELL, Captain ABNEY, and Professor STROUD, on the Action of Light upon Dyed Colours. Drawn up by the Secretary. THE primary object of the work of this Committee is to determine accurately the relative fastness to light of all the various colours at present employed by the dyer of textile fabrics. This is to be attained by exposing to direct sunlight and the ordinary atmospheric influences, patterns of silks, wool, and cotton, specially dyed with the various natural and artificial colouring matters. The work of purifying these colouring matters, dyeing the patterns, recording the dyed and faded colours of each pattern, &c., &c., must necessarily require much time. Moreover, owing to the very large number of colours to be examined, the long exposure needed to give useful results (one year at least), and the limited capacity of the exposing frame employed, the work will naturally proceed but slowly, and will extend over a period of some years. During the past year the Secretary of the Committee has been engaged in collecting samples of the colouring matters required for the investigation, and in making preliminary exposure experiments with the view of determining the best method of procedure to be adopted. Having decided to expose the patterns in groups according to colour, the work of purifying and dyeing with the red colouring matters has been begun, and is now in progress in accordance with a scheme in the hands of members of the Committee. Of the 20%. originally granted to the Committee at the last meeting of the Association in Leeds, the sum of 17. 10s. has been expended in the purchase of the necessary silk, wool, and cotton material, also an exposing frame, which has been erected at Adel in the neighbourhood of Leeds. Particulars of this expenditure have been forwarded by the Chairman of the Committee to the General Treasurer. Report (provisional) of a Committee, consisting of Professors M'LEOD and W. RAMSAY, and Mr. W. A. SHENSTONE (Secretary), appointed to investigate the Influence of the Silent Discharge of Electricity on Oxygen and other Gases. THE Committee regrets to state that, owing to various circumstances, very little further progress has been made during the past year. The necessary means for securing assistance in part of the work have, however, lately been secured, and its continued progress may therefore now be looked for; and it is recommended that the Committee be reappointed. No grant is asked for, as the necessary apparatus is at the command of the Committee. Third Report of the Committee, consisting of Professors H. M'LEOD (Chairman), ROBERTS-AUSTEN (Secretary), and REINOLD, and Mr. H. G. MADAN, appointed for the Continuation of the Bibliography of Spectroscopy. THE collection and verification of the titles of papers on spectroscopy have been continued during the past year, but there is not yet sufficient matter for publication. The Committee desire to be reappointed. |