32 Sir J. Norman Lockyer. 



Half of the negatives and glass copies of the remainder were con- 

 veyed to England in charge of Mr. Fowler, while the remaining half 

 of negatives and positives were sent home via Bombay. 



The general time signals were given by a bugler under Captain 

 Batten's orders. The chronometer was in charge of Lieutenant de 

 Wet, R.N. 



For the work of the prismatic cameras it was important to get a 

 signal as nearly as possible five seconds before the beginning of 

 totality, and, in order to eliminate the possible error of the chrono- 

 meter, it was arranged to determine this by direct observations. 

 Two methods were adopted. In one of them a boat was moored at a 

 distance of two miles from the camp, in the direction of approach of 

 the shadow, which would pass this point five seconds before totality. 

 This failed because of the indefinite boundary of the shadow. 



The otheir method was to determine when the visible remaining 

 crescent subtended an angle of 45 ; calculation showed that this 

 would occur at the desired interval from totality. This method was 

 completely successful. " 



The special signals during totality were given every ten seconds, 

 beginning at 127 the assumed period of totality by means of the 

 eclipse clock (which was started at the signal " go " by cutting a 

 thread thereby releasing the pendulum), by two timekeepers, one 

 during the first half, the other during the second half of totality. 



In the system adopted not only was the time left called out every 

 tenth second, but other signals were interpolated to guide the work 

 in the photographic huts. In order that there might be no mistake 

 about the calls, a spiral was drawn on the clock-face and the seconds 

 left plainly marked at the points which the second hand would 

 occupy during its two revolutions. 



In consequence of the perfect drill acquired at the rehearsals the 

 operations went off during the eclipse with absolute steadiness. They 

 commenced about one and a half hours before totality, ending after 

 a like interval after totality. Six volunteers were employed in the 

 timekeeping, including three with lamps which were not wanted. 



THE CHIEF INSTRUMENTS EMPLOYED. 

 The Prismatic Cameras. 



In the two prismatic cameras no less than fifty-seven photographs 

 were secured, the exposures varying from one to fifty seconds. 

 Such a result as this could only be obtained by a minute sub- 

 division of labour. In the case of each of these two instruments 

 six volunteers were employed, and they were distributed in the 

 following manner : 



One observer with the finder, his duty being to keep the image 



