144 



KEPOKT 1893. 



track, there would be no disturbance of its relation to the discharging 

 point. 



It is frequently observed in photographs of reduplicated flashes that 

 the various components do not follow absolutely similar paths, and it is 

 often seen that the departure from similarity is near the ground. 



Surely this is exactly what would be expected if the path of least 

 resistance were swept along as suggested. The movements of the wind 

 are not uniform, and the tube would frequently get bent or broken, such 

 an event being most probable to occur within reach of eddies from the 

 ground. It may be pointed out that the reduplicated flash photographed 

 by the secretary to your Committee in a stationary camera was taken at 

 right angles to that in which the storm and wind were travelling. 



Movement of the camera or lens or plate would necessarily exaggerate 

 the reduplication where it might not otherwise have been detected, but 

 there can be no doubt that a single discharge often lasts for several 

 seconds, and therefore that any path of minimum resistance created by 

 the first component flash must be moved to an extent quite sufficient to 

 reveal the multiple structure to the eye and to the camera. 



It seems, moreover, that the narrow ribbon structure may be attri- 

 buted to much the same cause. 



In conclusion, your Committee have to state that their scheme of an 

 atlas of typical clouds cannot be carried out without considerable expen- 

 diture, and they suggest that they be reappointed with a grant of 501. 

 As they did not draw the 161. voted last year, this is really an application 

 for only 35Z. for that which they believe would be a valuable piece of 

 work. 



The Best Methods of Recording the Direct Intensity of Solar 

 Radiation. — Ninth Report of the Committee, consisting of 

 Sir Gr. Gr. Stokes (Chairman), Professor A. Schustee, Mr. G-. 

 Johnstone Stonet, Sir H. E. Koscoe, Captain W. de W. Abney, 

 Professor H. McLeod, and Mr. Gr. J. Stmons. {Draivn up by 

 Professor McLeod.) 



During the last year Mr. Casella has constructed for the Committee a 

 thermometer with a lenticular bulb similar to that described in previous 

 Reports, but consisting of colourless instead of green glass. As stated in 

 the last Report, there are great difliculties in constructing an instrument 

 with a green-glass bulb, and it was believed that there would be little 



