230 Mr. H. F. Newall. 



Result. In the event I used A about 40 seconds after the beginning 

 of totality, and found no trace of polarisation in any position of the 

 instrument. To make sure that nothing was wrong I used also polari- 

 scope B, and corroborated the first observation. 



Towards the end of the third minute 2 m 50 s from the beginning of 

 totality I again observed with B. At the end of the fifth minute I used 

 C ; and in neither case could I detect a trace of atmospheric polarisation. 

 About 3.50 P.M., after the eclipse was over, I used the polariscopes 

 again, and found them all as adjusted in the morning before the 

 eclipse ; each one showed showed strong bands on the patches of blue 

 sky visible in the field of view. 



15. The Quartz"jSpedrograph, 

 It was intended to attempt to get 



(i) Photographs of the ultra-violet spectrum of the flash at the 



beginning and end of totality, 

 (ii) A photograph of the ultra-violet spectrum of the corona. 



The instrument was fixed on the top of the double tube, arid was 

 supplied by light from the ccelostat. The arrangement was such that 

 the slit could be set, without readjustment of the image, to catch the 

 crescents both at beginning and end of totality, and the corona during 

 totality. No other medium but quartz was used in the lenses and 

 prisms, and the dimensions were such that a 2-inch beam was trans- 

 mitted. The image lens had a focal length of 20 inches, and the 

 collimator and camera lenses were each of focal length 18 inches; the 

 prism was compounded of two 30 prisms, one of right-handed and the 

 other of left-handed crystal ; all the optical parts were constructed by 

 Hilger. Unfortunately it was found impossible to get the adjustments 

 completed before the eclipse. 



On the morning of the eclipse a final attempt was made, and it was 

 thought well to make the exposures according to programme. These 

 were all duly made, but the adjustment was so imperfect that the 

 photographs are useless, which is all the more regretable as the plates 

 show strong spectra. 



16. Photographic Objective-grating Camera. 

 It was intended to attempt to get 



(i) Photographs of the " flash" spectrum with high dispersion in a 

 limited range of spectrum, to assist in the discussion of the 

 origin of lines, whose wave-lengths it was hoped would be 

 determined accurately by means of the 4-prism spectroscope. 



(ii) A photograph of the blue coronal ring near A 4231, for com- 

 parison with the visual observations of the green coronal ring. 



