METEORS AND COMETS. 661 



-earth, was found to be covered with ice. The majority of the meteors that strike 

 the earth are stone, and not iron, as is commonly supposed. Some, however, 

 are of pure iron. Out of the 500 or 600 meteoric stones that have been found 

 on the earth and preserved not more than ten were iron. 



Meteoric particles are striking the earth all of the time. Some astronomers 

 estimate that as many as 10,000,000 particles strike the earth each day, while the 

 lowest estimate puts the number at 7,500,000 per day. Many more of these parti- 

 cles strike the earth in the morning than at night, and frequently observing persons 

 in their morning walks can plainly see evidences of the meteoric showers. These 

 meteoric particles seem to be circulating in space, and the earth as it moves in its 

 orbit strikes against them. Some of the meteoric showers are very copious and very 

 bright. One writer has likened a meteoric shower that he saw to a snow-storm, 

 the flakes being of fire instead of congealed vapor. Astronomical observers Jiave 

 detected, by means of the spectroscope, sodium, magnesium and sometimes iron 

 in these bright shooting stars. One consequence of this constant falling of meteoric 

 particles is that the earth is growing larger, but the lecturer said that there was no 

 immediate danger of any radical change taking place in the surface of this sphere, 

 for at the present rate of the meteoric fall, it would take 500,000,000 years for 

 the earth to gain one inch of surface. Meteors are known to come in periodical 

 showers, probably the most remarkable being the shower that occurs about the 

 I ith or 12th of November. It appears that meteors follow in the track of comets. 

 They are related to comets in some way or another, but exactly how the lecturer 

 was not prepared to say. Some scientists thought that the meteors were the 

 debris or cast-off particles of comets, while others thought that perhaps the comets 

 were simply aggregations of meteoric particles, and the falling stars were the part- 

 icles that did not get into the aggregations. It is certain, at any rate, that flocks 

 of meteors follow the various comets at few millions of miles behind. 



Comets, Prof. Young said, had always been puzzles to the astronomers and 

 terrors to the superstitious. It had been seriously urged that comets were the 

 forerunners of unhealthy and disastrous periods on the earth, but such beliefs 

 had been vigorously ridiculed by scientists. The modern improvements in tele- 

 scopes had caused a rapid increase in the number of discovered comets. These 

 strange bodies are now being discovered at the rate of five or six every year. 

 There are 650 comets in the catalogue at present, very few of which are bright 

 ones, however. According to the most trustworthy astronomical statistics there 

 were twenty-three bright comets between the years 1500 and 1600, twelve bright 

 comets between 1600 and 1700, eight between 1700 and 1800, nine between 1800 

 and 1850^ and since then there have been ten bright comets visible. The comets 

 seen during the last few years were more or less remarkable. Astronomers be- 

 come very enthusiastic in their search for comets. One ardent scientist bewailed 

 the death of his wife a few years ago because the event lost him a comet, which 

 a competitor happened to discover. There are about fifty comets that move in 

 elliptical orbits. The theory is that each of these comets has been caught by 

 some planet and held captive, being compelled to move around and around in 



