12 Field Columbian Museum — Geology, Vol. i. * 



It is therefore possible when any body possessing these characters is 

 found upon the earth, to assert with comparative certainty that it 

 was of meteoric origin though its fall to the earth has not been ob- 

 served. This is called a meteoric " find " in distinction from a meteo- 

 ric "fall" and a large number of the meteorites now in collections 

 have been obtained in this way. 



This is especially true of the meteorites made up chiefly of iron, 

 since their metallic character preserves them from decay and their 

 weight and difference from ordinary stones make them noticeable to 

 the ordinary observer. On account of the nickel-white color of their 

 interior also, they are often taken by their discoverers for masses of 

 silver and have been preserved for this reason. Of more than one 

 hundred localities of these now represented in collections only nine 

 metallic meteorites have actually been seen to fall. 



The meteoric stones, on the other hand, unless their fall has been 

 observed, are far less likely to be discovered, since they differ so little 

 from ordinary stones in appearance that they are easily overlooked 

 and under atmospheric influences quickly disintegrate and decay. 

 Hence most of the stony meteorites now in collections have been 

 seen to fall. 



Over 530 distinct meteoric falls and finds are now known, of 

 which the falls number about 270. 



It has already been noted that but a small proportion of the meteor- 

 ites which actually reach the earth are ever secured, since numbers 

 of them fall into the sea or upon uninhabited regions. It will there- 

 fore be evident that any conclusions regarding the distribution of 

 meteorites which may be drawn from maps showing where they have 

 fallen must be imperfect and faulty. Such observations as have been 

 made, however, indicate that meteorites are not attracted to any par- 

 ticular portion of the earth's surface and that the point at which they 

 reach the earth is purely a matter of accident. 



The times both of the year and of the day, at which meteorites 

 fall, seem to be somewhat more regular. 



A table compiled by Mr. R. P. Greg,* shows that more meteor- 

 ites have fallen in June and July and less in December and January 

 than in the other months. 



A similar comparison of data by Haidinger,f regarding the times 

 of day at which meteorites fall, shows that more have fallen in the 

 afternoon than in the forenoon. This is a result, as shown by Pro- 

 fessor H. A. Newton, \ of their movement in direct rather than in 

 retrograde orbits, i. e. of their following the earth. 



"London Phil. Mag., November, 1854. 



tSitzungsb. d. k., Ak., d, Wissensch., Vienna, 1867. 



jAm. Jour. Sci., 3rd Ser , Vol. 36, p 1-14. 



