128 



Mr. J. N. Lockyer. 



[Nov. 17, 



Konkoly and Professor Herschel are among the authorities which 

 may be cited for the above statement. 



" On August 12, 13, and 14 I observed a number of meteors 

 with the spectroscope; amongst others, on the 12th, a yellow fireball 

 with a fine train, which came directly from the Perseid radiant. In 

 the head of this meteor the lines of lithium were clearly seen by the 

 side of the sodium line. On August 13, at lOh. 46m. 10s., I observed 

 in the north-east a magnificent fireball of emerald-green colour, as 

 bright as Jupiter, with a very slow motion. The nucleus at the first 

 moment only showed a very bright continuous spectrum with the 

 sodium line ; but a second after I perceived the magnesium line, and 

 I think I am not mistaken in saying those of copper also. Besides 

 that, the spectrum showed two very faint red lines."* 



" A few of the green ' Leonid ' streaks were noticed in November 

 (1866) to be, to all appearances, monochromatic, or quite undispersed 

 by vision through the refracting prisms ; from which we may at least 

 very probably infer (by later discoveries with the meteor-spectroscope) 

 that the prominent green line of magnesium forms the principal con- 

 stituent element of their greenish light. "f 



Again, later on in the same letter, Professor Herschel mentions 

 Konkoly's observations of the bright b line of magnesium, in addition 

 to the yellow sodium line in a meteor on July 26, 1873. 



I again quote from Professor Herschel : — 



" On the morning of October 13 in the same year, Herrvon Konkoly 

 ^again observed with Browning's meteor-spectroscope the long-enduring 

 .streak of a large fireball, which was visible to the north-east of 

 O'Gyalla. It exhibited the yellow sodium line and the green line of 

 magnesium very finely, besides other spectral lines in the red and 

 green. Examining these latter lines closely with a star-spectroscope 

 attached to an equatorial telescope, Herr von Konkoly succeeded in 

 identifying them by direct comparison with the lines in an electric 

 Oeissler-tube of marsh-gas. They were visible in the star-spectro- 

 scope for eleven minutes, after which the sodium and magnesium 

 lines still continued to be very brightly observable through the meteor- 

 ^spectroscope.";!; 



The green line " b " of magnesium occurring as a bright line in 

 luminous meteors indicates that their temperature when passing 

 through our atmosphere is higher than that of the bunsen, and we 

 may add of comets as generally observed, although some exhibit the 

 b lines of magnesium and those of iron when at perihelion, as shown 

 later on. 



The two lines which Konkoly supposes are probably due to copper 



* Konkoly, ' Observatory,' vol. 3, p. 157. 



f Herschel, letter to ' Nature,' vol. 24, p. 507. 



X Ibid. 



