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POrULAH SCIENCE REVIEW. 
the solar envelopes, it may not be without great interest to allude 
another point conclusively decided during the last annular eclipse of the 
sun, observed by Mr. Pogson on June C of this year, as described by him in 
a letter to Sir George B. Airy. In 1870 Professor Young was the first to 
observe the reversal of the Fraunhofer lines in the stratum closest to the 
sun. Now, in 1871 doubts were thrown upon the subject. It appears that 
the reversed lines seem to have been satisfactorily observed by Captain 
Maclear at Bekul, Colonel Tennant at Dodabetta, and Captain Fyers at 
Jaffna. The observations of Pringle at Bekul, Respighi at Poodacottah, 
and Pogson at Avenashi were doubtful, while Mosely at Trincomalee saw 
nothing of this reversal, which is, according to all accounts, a most striking 
phenomenon, although of very short duration. Mr. Lockyer missed it by an 
accidental derangement of the telescope. The reversal and the physical 
deductions from it are placed beyond doubt by Mr. Pogson’s observations of 
the annular eclipse on June 6. At the first internal contact, just after a 
peep in the finder had shown the moon’s limb lighted up by the corona, he 
saw all the dark lines reversed and bright, but for less than two seconds. 
The sight of beauty above all was, however, the reversion of the lines at the 
breaking up of the limb. The duration was astonishing — five to seven 
seconds ; and the fading out was gradual, not momentary. This does not 
accord with Captain Maclear’s observations in 1870, who reports the disap- 
pearance of the bright spectrum as ‘not instantly, but so rapidly that l 
could not make out the order of their going.’ Professor Young, again, says 
that 1 they flashed out like the stars from a rocket-head.’ But discrepancies 
in this minor point may be accounted for by supposing differences in 
quietude of that portion of the sun’s limb last covered by the moon.” 
Dr. Huggins’s Spectroscopic Observations of Nebulce. — On this subject 
Dr. Dela Rue remarks: “ Although, as I have stated, I do not contemplate 
passing in review recent discoveries in astronomy, I must not omit to call 
your attention to some few subjects of engrossing interest. First, with re- 
ference to the more recent work of Dr. Huggins. In his observations he 
found that the brightest line of the three bright lines which constitute the 
spectrum of the gaseous nebulae was coincident with the brightest of the 
lines of the spectrum of nitrogen ; but the aperture of his telescope did 
not permit him to ascertain whether the line in the nebulae was double, as 
is the case with the line of nitrogen. With the large telescope placed in 
his hands by the Royal Society, he has found that the line in the nebulae 
is not double, and in the case of the great nebula in Orion it coincides in 
position with the less refrangible of the two lines which make up the cor- 
responding nitrogen-line. He has not yet been able to find a condition of 
luminous nitrogen in which the line of this gas is single and narrow and 
defined like the nebular line.” 
Stellar Motions of Recess and Approach — u Dr. Huggins has extended,” 
says Dr. De la Rue, “the method of detecting a star’s motion in the line of 
sight by a change of refrangibility in the line of a terrestrial substance exist- 
ing on the star to about 30 stars besides Sirius. The comparisons have been 
made with lines of hydrogen, magnesium, and sodium. In consequence of 
the extreme difficulty of the investigation, the numerical velocities of the 
stars have been obtained by estimation, and are to be regarded as provisional 
