312 Royal Astronomical Society. 



(on the coast), for the purpose of observing it. It was necessary to 

 be very precise in this calculation, and also to be very certain of the 

 geographical position of the spot selected for observing the eclipse, 

 on account of the almost exact correspondence in size of the sun's 

 and the moon's discs. Mr. Caldecott, in the first place, proceeded 

 by sea to Mahe (a little to the south of Tellicherry), and thence up 

 the Mahe river towards its source, and having, by a careful survey 

 of the river, ascertained its position with respect to Mahe (whose 

 latitude and longitude he had previously ascertained), he selected a 

 clear and open space on a rising ground, about three miles north of 

 it, and there pitched his tent at midnight of December 20. He had 

 brought with him an excellent 30-inch achromatic telescope, having 

 an object glass of 2| inches aperture, with an eyepiece giving a mag- 

 nifying power of about 50, protected by a smoked glass gradually 

 increasing in intensity from one end to the other, and sliding easily 

 in a groove, wherewith to observe the eclipse ; a sextant and arti- 

 ficial horizon, with a good pocket watch for time ; and two native as- 

 sistants, with an actinometer for observing the rate of decrease of 

 solar radiation. 



At daylight on the 21st (civil reckoning), the author mounted his 

 telescope on a stand having a very smooth parallactic motion, and 

 made all the necessary preparations, taking a set of altitudes of the 

 sun's lower limb at about 7^ a.m., and stationing the native observers 

 at the actinometer. He began watching the point of the sun's disc, 

 where the edge of the moon's limb was to impinge at 7^ 35™, the 

 sky being at this time quite clear in every direction, with the excep- 

 tion of a few light fleecy clouds which hung about the sun, but which 

 cleared away before the eclipse became total. The observations that 

 follow were taken almost verbatim from the author's notes written 

 during the progress of the eclipse. At 7^ 38" 49^, corrected mean 

 solar time, civil reckoning, the contact was evident, though the real 

 first contact was probably two or three seconds earlier. With one 

 digit eclipsed the border of the moon was fully as tremulous as that 

 of the sun, and no hollows or coruscations were to be seen. No ap- 

 pearance of any inherently bright spots about the moon's disc was 

 observed about this time, and no spots on the sun. The cusps were 

 perfectly sharp and distinct ; the colour of the sun a pearly white, 

 inclining to a metallic or silvery white. With eleven digits eclipsed 

 there was no appearance of a corona, but shortly after three protu- 

 berances were observed near the southern cusp, and none on the 

 other. [This is illustrated by a drawing.] As the conjunction of 

 the discs approached, Mr. Caldecott watched very closely for the 

 "beads," but saw none until the very instant of conjunction, when 

 the whole of the southern limb of the sun broke up into most beau- 

 tiful beads of silvery light, with a clear but very fine line of light 

 joining them, and extending somewhat beyond them, until lost in 

 the corona of the opposite limb. [This is illustrated by a drawing.] 

 These beads for the second or two of their remaining, appeared to 

 form, break up, and form again, and resembled globules of mercury 

 of different sizes in a state of violent agitation. 



They never entirely disappeared, so that the sun wanted the small- 



