214 0. C. Farrington — Times of Fall of Meteorites. 



Tabulation of meteorite falls by days of the year seems to 

 show little of significance. The largest number of falls for any 

 one day is five on October 13, and this is a month when the 

 total number of falls is not large. Four days of the year show 

 four falls each and 158, or nearly half the total number, no falls 

 at all. The days without falls seem to be scattered indiscrimi- 

 nately through the year, without marked grouping or arrange- 

 ment. The days showing falls aside from those mentioned 

 have from one to three falls each without any marked grouping 

 that is apparent. Such a record seems also to indicate that to 

 refer a meteorite falling on the day of a star shower to such a 

 shower is unsafe, especially if the observations are not sufficient 

 to assign the two to the same radiant. Meteorite falls are so 

 distributed throughout the year that the two occurrences 

 might easily be coincident without being otherwise related. 



Of all times of fall of meteorites the most satisfactory for 

 study are probably the hours of fall, since the ratio of number 

 of falls to number of hours is larger than to days, months or 

 years. As is well known, the hours of fall show the direction 

 of movement of meteorites, since (with a few minor possible 

 obvious exceptions) meteorites falling from noon to midnight, 

 or afternoon falls, must be moving in the same direction as 

 the earth; while those falling between midnight and noon are 

 moving in a direction opposite to that of the earth or else at a 

 speed so slow that they are overtaken by it. While the hour of 

 fall is not known of as many meteorites as is the year and 

 month, yet of 268 sufficiently satisfactory records are available. 

 Of these 268 falls 180 occurred in the time from noon to 

 midnight, and 88 from midnight to noon. Meteorites, there- 

 fore, in the proportion of at least two to one, have direct motion 

 and overtake the earth. Of the others it is probable that the 

 majority have retrograde motion, since observations indicate 

 that but few, comparatively, are traveling at so slow a speed as 

 to be overtaken by the earth. As in the case of the months and 

 the years, it is quite likely that here also considerable allowance 

 should be made for conditions of observation. It is reasonable 

 to expect that the number of falls recorded in the early morn- 

 ing hours would be less than that for other times, since man- 

 kind is generally asleep then. That some such allowance must 

 be made is indicated by the records, for the number of falls 

 from midnight to 6 a.m. is only 21, while from 6 a.m. to noon 

 it is 67; from noon to 6 p.m. 122, and from 6 p.m. to midnight 

 58. Hence it seems probable that some of the diminution in 

 the number of falls is due to lack of observers, although New- 

 ton* concluded from studies of the orbits of the morning falls 

 that the lack of observers had little to do with their scarcity. 



*This Journal (3), xxxvi, p. 10, 1888. 



