266 Total Eclipse of the Sun, 1901, May 18. 



This negative is fainter then any of the others, but shows well the 

 detail and prominence in the south-west region of the corona. 



4. The Waters Camera. 



This is a Dallmeyer portrait combination of 2 inches aperture and 

 8 feet equivalent focus, a Dallmeyer telephoto lens being used as a 

 negative enlarger. The photographs were taken on half plates. The 

 enlargement is rather too great for detail of any importance to be 

 shown, and there is therefore no need to describe them in detail. 

 Exposures of about a quarter of a second were given in all cases. 



No. 1. Exposed at second contact. Plate, Imperial Special Rapid. 

 No. 2. Exposed at 40 seconds. Plate, Imperial Special Kapid. 

 No. 3. Exposed at 80 seconds. Plate. Imperial Flashlight. 

 No. 4. Exposed at 120 seconds. Plate, Imperial Flashlight. 

 No. 5. Exposed at 160 seconds. Plate, Imperial Flashlight. 

 No. 6. Exposed at 200 seconds. Plate, Imperial Special Kapid. 



5. The Pinhole Camera. 



This was a camera with pinhole aperture of ^V of an inch, and 

 the plate was placed at a distance of 30 inches. The plate was 

 exposed immediately before second contact, and closed immediately 

 after third. A small arc of sunlight is thus seen both on the east and 

 west limbs of the Moon. A coronal ring, about 4 minutes in greatest 

 height, is seen connecting these arcs. The little photograph has of 

 course no scientific value, but as being the only instance of a photo- 

 graph of the corona taken with a pinhole, it may rank as a curiosity. 

 The ratio of aperture to focal length was as 1 to 960, and the exposure 

 given to the plate would correspond to one of y^th of a second, as 

 given with the Newbegin. The plate used was an Imperial Special 

 Eapid. 



6. Photographs of the Landscape. 



At my request M. Alexander Rambert, a professional photographer 

 of Mauritius, took a series of photographs of the landscape during the 

 coming on and passing off of the shadow. The same exposure was 

 given in every instance, the plates were all from the same batch, and 

 they were developed at one and the same time, in the same bath and 

 for the 'same length of time. The exposures were made at regular 

 intervals of 5 minutes, the first being taken 27 minutes before mid- 

 totality, the last 27| minutes after. A comparison of the plates taken 

 before totality with those taken at corresponding times after, shows a 

 slight but appreciable increase in density in the later plates as com- 

 pared with the earlier, but perhaps not more than would be accounted 

 for by the increase in altitude of the Sun. 



