118 FRAGMENTS OF SCIENCE. 



I was provided with a telescope of admirable definition, 

 mounted, adjusted, packed, and most liberally placed at 

 my disposal by Mr. Warren De La Rue. The telescope 

 grasped the whole of the sun, and a considerable portion 

 of the space surrounding it. But it would not take in the 

 extreme limits of the corona. For this I had lashed on to 

 the large telescope a light but powerful instrument, con- 

 structed by Ross, and lent to me by Mr. Huggins. I was 

 also furnished witli an excellent binocular by Mr. Dallmeyer. 

 In fact, no man could have been more efficiently supported. 

 It required a strict parceling out of the interval of totality 

 to embrace in it the entire series of observations. These, 

 while the sun remained visible, were to be made with an 

 unsilvered diagonal eye-piece, which reflected but a small 

 fraction of the sun's light, this fraction being still further 

 toned down by a dark glass. At the moment of totality 

 the dark glass was to be removed, and a silver reflector 

 pushed in, so as to get the maximum of light from the 

 corona and prominences. The time of totality was dis- 

 tributed as follows: 



1. Observe approach of shadow through the air: totality. 



2. Telescope . . 30 seconds. 



3. Finder 



4. Double image prism 



5. Naked eye . 



6. Finder or binocular 



7. Telescope . 



8. Observe retreat of shadow. 



30 seconds. 

 15 seconds. 

 10 seconds. 

 20 seconds. 

 20 seconds. 



In our rehearsals Elliot stood beside me, watch in hand, 

 and furnished with a lantern. He called out at the end of 

 each interval, while I moved from telescope to finder, from 

 finder to polariscope, from polariscope to naked eye, from 

 naked eye back to finder, from finder to telescope, aban- 

 doning the instrument finally to observe the retreating 

 shadow. All this we went over twenty times, while look- 

 ing at the actual sun, and keeping him in the middle of 

 the field. It was my object to render the repetition of the 

 lesson so mechanical as to leave no room for flurry, forget- 

 fulness, or excitement. Volition was not to be called upon, 

 nor judgment exercised, but a well-beaten path of routine 

 was to be followed. Had the opportunity occurred, I 

 think the programme would have been strictly carried 

 out. 



