256 REPORT — 1875. 



In the ' Astronomischc Nachrichten' (No. 2064), Herr N. v. Ivonkoly de- 

 scribes results of some spectroscopic observations of tbo PerscVds of August 

 187-4, examined by means of a Browning's meteor-spectroscope. The spectra 

 of 130 meteors on the nights of the 7th, 8th, and 10th to 12th of August, vary- 

 ing in brightness from 1st to -tth magnitude stars, showed continuous colours, 

 yellow and green predominating chiefly in all the nuclei, violet being always 

 and indigo mostly absent, and red only bright in those which were markedly 

 red-coloured. The spectra of the streaks were very various, those of di- 

 stinctly yellow meteors showing only the double yellow line of sodium (always 

 present in the streaks, and serving as a micrometric zero from which the 

 positions of the other bright lines could be relatively estimated). In the streak- 

 spectra of green meteors the green lines of magnesium were also visible ; and 

 in some of red colour red lines, apparently those of strontium, or of strontium 

 and lithium, were observed. Some of these meteors were brighter than 

 Venus, and left streaks which lasted for 30 or 40 seconds. The streak of one 

 which remained visible for 15G seconds was observed with the spectroscope 

 for 30 seconds. Not only the bright lines of sodium and magnesium, but 

 many other bright lines, especially in the green, and some also in the blue, 

 were seen, which were regarded as probably due to the presence of iron and 

 copper in the substance of the streak ; a cotton-ball dipped in alcohol and in- 

 flamed, having particles of sodium, magnesium, and ii'on with very little copper 

 in its fibres, exhibited, when tossed into the air, a very similar spectrum, while 

 no other combination tried produced a similar effect. 



The following important paper by Dr. G. Tschermak on the meteorites of 

 Lance (1872, July 23rd) in the fifth volume (pt. i. Jan. 1875) of his 'Minera- 

 logische Mittheiluugen,' shows that (as was found by Daubree in the meteorites 

 of Aumale, 1865, Aug. 25th) aerolites that fell about the period of the August 

 meteor-shower have more than once presented the rare occurrence of sodium 

 chloride in their composition. The appearance and general course pursued 

 by this fireball is described with imusual completeness in a work by M. 

 Nouel*, of Vendome, in the neighbourhood of which town the meteorites fell ; 

 and the fireball was very generally observed. 



Dr. Tschermak's paper treats of the chemical analysis and of the micro- 

 scopic examination of thin sections of the stone ; and besides eleven admi- 

 rable lithographic representations of the latter, it contains three plates of the 

 external appearance of the largest of the stones (found in three pieces at the 

 bottom of a hole Ik metre deep) from difterent points of view, the directions 

 of the slag-fibres on its crust showing clearly how the fj-ont or pyramidal 

 part and back or flattened base of the stone had been differently exposed to 

 tlie rushing and smelting blast of heated air through which it forced its way 

 point foremost with apparently only one or two slight oscillations. The draw- 

 ings of thin sections exhibit ' microscopic views of spherules of great variety, 

 of a clear olivine crystal, and of one {the onJij unrounded one observed) of 

 bronzite. Among the spherules a remarkable one of bronzite is immediately 

 recognized by the numberless cleavages and cross cleavages exliibited by its 

 structurally prismatic crystal. Other spherules are of transparent olivine with- 

 out radial structure ; and some are of highly composite characters, appearing 

 occasionally to have been incrusted or metamorphosed externally and con- 

 centrically to a certain depth, but found by polarized light to possess only 

 apparent radial and in reality excentrical crystalline structure when sub- 



* Notice sur le bolide du 23 Juillet 1872 qui a projet6 des meteorites dans le canton 

 de St.-Amand, arrondissement de Vendorae, departeineiit de Loire-et-Oher, par M. Nouel. 

 Yendome, 1873. 



