454 SCIENCE PROGRESS 



nature. Mr. Lockyer, in the Bakerian lecture (1888), said that 

 " the vapours given out by the meteorites as the sun is 

 approached are in an approximate order : slight hydrogen, 

 slight carbon compounds, magnesium, sodium, manganese, lead, 

 and iron." Of course the meteorites which have fallen to the 

 earth can be subjected to proper analysis. Mr. Fletcher says 

 that they evolve hydrogen, nitrogen, marsh gas and the 

 carbonic oxides when heated. No entirely novel elementary 

 body has been discovered in meteorites, nor can an organic 

 origin be claimed for anything found in them. Browning and 

 Konkoly, from observations of meteors in luminous flight, 

 inferred the presence of the sodium line; and in the fireball 

 of October 13, 1873, Konkoly remarked bands which he 

 identified with the spectrum of a hydro-carbon. In 1908 

 there were 580 meteorites or fragments of meteorites in the 

 British Museum, and the collection is increasing every year. 



There was a great advance in our knowledge of meteors and 

 their attendant phenomena between 1800 and 1900. At the 

 former period relatively nothing was known of these phenomena, 

 and the most crude and erroneous ideas prevailed concerning 

 them. Now everything is changed. Meteors have but acquired 

 their right in being acknowledged to rank with the planetary 

 bodies of our solar system. Our knowledge of them will 

 continue to increase, and it is quite possible they will grow in 

 importance. In the future master minds will arise to amend our 

 theories consistently with observation, and the materials we 

 have been accumulating may form the framework of a cos- 

 mogony differing much from present ideas. 



With regard to meteors coming from known comets, we can 

 hardly expect, when all the conditions are considered, many 

 cases of well-assured character. There are very few comets 

 with orbits passing near the earth's path. Prof. Herschel 

 carefully examined the orbits of eighty comets which appeared 

 between 1872 and 1892, and found that only two of these made 

 relatively near approaches to the earth, viz. Denning's comet of 

 1881, with path at one point only 3 millions of miles distant, 

 and Finlay's comet of 1886, about 4^ millions of miles distant. 

 Whether comets at this distance are capable of inducing a 

 meteoric shower is uncertain ; but it is a fact that some of these 

 bodies spread their material over vast tracts of the sky. The 

 tail of a large comet may be 50 millions of miles in length, 



