CHAP. VIII. merable black lines, which is the very cypher of the universe, but which nevertheless has been read a little. With which of the black lines did these newly-discovered and

all-eloquent bright lines coincide? Here the eclipse gave out an uncertain sound. In due course of time we received detailed accounts from three of the expeditions, under Captain Herschel, Major Tennant, and M. Stephan re

spectively, and representing the Royal Society, the Royal CHAP. VIII. Astronomical Society, and the Bureau des Longitudes. In the detailed accounts, although it was clear that every man had tried his utmost, there was not such great subject of congratulation as there had been in the telegrams. There was still one part of the question unsettled. All the observers had observed bright lines, but they were not

certain as to the positions of some of the lines, and the accounts were discordant among themselves. Premising that the principal black lines in the solar spectrum are lettered from the red towards the lavender end, the following results will be readily understood. Captain Herschel

wrote:

"I consider that there can be no question that the orange line was identical with D, so far as the instrument is com

CHAP. VIII. petent to establish an identity. I also consider that the identity of the blue line with F is not established, but, on the contrary, I believe the former is less refracted than F, but not much. With regard to the red line, I hesitate very much in assigning an approximate place. It might have been near C; I doubt its being as far as B, but there would be the limit. I am not prepared to hazard any more definite opinion about it. Its colour was a bright red."

Tennant.

Rayet.

Discre

pancies.

Major Tennant saw five lines, three of them corresponding to C, D, and b, one in the green near F, and possibly one near G.

M. Rayet (in M. Stephan's party) saw nine lines, corresponding to B, D, E, b, F, and the others undetermined.

It is obvious from these discrepancies, which we hold to be entirely unavoidable in such a delicate investigation,

carried on under difficulties of weather and under con- CHAP. VIII. ditions so out of the common, that the question as to the nature of the red flames-our knowledge of which depended upon a rigorous determination of the position of the lines -was left open; and it seemed very much as if, after all, the problem would be left in uncertainty and doubt until

another total eclipse with its attendant phenomena swept over the earth. A total eclipse of the sun is an awful phenomenon, and it was scarcely to be expected that in its presence a tremendous problem should be solved at the very first attempt. All the observers found all their laborious preparations of many months culminating in a