252 Mr. E. W. Maunder. 



With the 6-inch equatorial of the Mauritius Observatory : 

 F. T. Piggott Observed with the 6-inch equatorial. 

 N. Y. Olivier Recorder to Mr. Piggott. 



The following was the method of procedure, which was careftilly 

 rehearsed many times on May 16 and 17. The observers took their 

 places at their instruments, and Mr. Claxton watched the diminishing 

 arc of the Sun on the ground glass of the photoheliograph, and at 

 30 seconds before second contact gave the word to " Stand by." 

 At 20 seconds I gave the word to Sergeant-Major Wade to begin 

 the exposure of the plates in the prismatic camera. At 10 seconds, 

 when the arc of sunlight had lessened down to one of 49, Mr. 

 Claxton called " Ten," the signal to Staff-Sergeant Smith to start 

 the 10-seconds striking eclipse clock, and Staff-Sergeant Smith called 

 the number of the bells as they rang out at every tenth second from 

 this moment until some time after third contact. The exposures at 

 the different cameras were then made at the sound of the bells, and 

 Lieutenant F. W. Robertson, R.E., entered the time of each bell as it 

 rang ; a very simple arrangement, which worked smoothly and well, 

 and gave the times of exposure of the different plates very closely. 



The Day of the Eclipse. The weather at eclipse time i.e., from 

 6 h 51 to 9 h 5 m A.M. had been by no means promising for the first 

 three weeks after landing, but had tended to improve later. The 

 morning of May 18 was the first upon which the Sun had been 

 entirely free from cloud at the time of totality, 7 h 53 m A.M., and even 

 on that morning first contact was lost by the interposition of a dense 

 bank of cloud, which came up from the east soon after sunrise and 

 overtook the Sun. It passed away in a few minutes, and the first 

 photograph of the partial phase was taken at 16 minutes after the pre- 

 dicted time for first contact. Light scud continued to pass over the 

 Sun for about 40 minutes more, but got thinner and lighter as totality 

 drew on, and about 2| or 3 minutes before second contact the entire 

 eastern half of the sky was free from cloud, and remained so until 

 after fourth contact. But though the sky was thus apparently clear 

 there was evidently much moisture in the air, since at Quatre Bornes, 

 13 miles to the south-west, the total phase was observed in a smart 

 drizzle of fine rain; and at Curepipe, 16 miles to the south, it was 

 entirely lost by thick cloud. The images also, as seen upon the 

 ground glasses of the photoheliograph and coronagraph, were very 

 unsteady, the Sun's limb "boiling" excessively. This "boiling" 

 effect would seem to have been less noticeable in the 6-inch equatorial 

 mounted in a dome on the roof of the Observatory main building, and 

 in the Newbegin telescope brought by Mrs. Maunder and mounted in 

 the photoheliograph dome of the Observatory, and which were there- 

 fore at a considerable elevation, than in the instruments fed by the two 



