1868.] 



Solar Eclipse of 1868. 



Ill 



"visible in finder." It was therefore almost always necessary to find with 

 the principal, by the setting ; and afterwards either to exchange the light 

 eyepiece for the heavy spectroscope (removing at the same time a coun- 

 terpoise) without disturbing the direction, if possible, or to take the bear- 

 ings of the most conspicuous stars visible in the finder. But as there never 

 was and never could be any certainty that in the act of insertion a disturb- 

 ance sufficient to displace the image from the position the slit should oc- 

 cupy would not take place, the latter method became the surest, if the most 

 troublesome. [The connecting-tube, I should remark, cost me, literally, 

 days of worry and grinding before I could induce it to slide in and out at 

 all.] If after these precautions the result of a blind search was negative, 

 the whole had to be done de novo. What with removing and replacing the 

 spectroscope, inserting eyepieces and counterpoises, setting the readings, 

 searching in both finder and telescope, winding the driving-clock over and 

 over again, in endless combination, all by the light of a bull's-eye lantern, 

 perhaps without catching a single spectrum all night, I often found four 

 or five hours' observing (?) more fatiguing than a long walk. 



It may appear strange that I did not replace the finder by a better 

 telescope. I can only say that India is not England, and Bangalore is not 

 London. The idea did not occur to me as a practical one, and I was ner- 

 vously afraid of making any alteration which might leave me worse off than 

 I was. A bad finder was after all no great matter, for the eclipse and the 

 nebulae could wait. At the same time I wish now that my finder had 

 been more serviceable as a telescope for I got ; but a poor sight of the eclipse 

 with it. 



19. Further preparations, Observatory, fyc. 

 To return to my preparations. In the utter absence of any precise 

 knowledge of the appearances which would be presented, but anticipating 

 a faint spectrum as the most probable, all my preliminary arrangements 

 had in view as complete an exclusion of external light as practicable. A 

 wooden frame was constructed for an observatory with a revolving roof, the 

 latter being covered with painted canvas. A large black curtain was pro- 

 vided, through the centre of which were to be passed the observing-end of 

 the telescope and finder, and the declination-clamp and slow-motion screw. 

 A segment of the octagonal observing-chamber would thus be in a great 

 measure protected from the light which might be expected to enter the 

 limited aperture in the roof. 



20. The Expedition leaves Bangalore. 

 The instruments, observatory, and camp-equipage started from Bangalore 

 on the 7th of July, and reached on the 7th of August — a creditable march of 

 390 miles in 31 days (including halts) in the height of the rainy season. 

 My subsequent experience of the state to which so-called "made" roads 

 may be reduced, in these parts of India, by a few days' rain, afforded grounds 



