312 KANSAS CITY REVIEW OF SCIENCE. 



That most birds of prey are destructive to game birds, songsters and certain 

 game mammals. 



And finally, that all migrations of all migratory birds of prey are conducted 

 on a basis of food supply and not from any insufficiency of feathering or delicacy 

 of structure. — American Field. 



ASTRONOMY. 



METEORIC SHOWER OF AUGUST lo, 1882. 



WILLIAM DAWSON. 



It is believed by those who make a study of the matter, that about the loth 

 day of August the earth passes through a body, or stream, of meteoric matter by 

 which an unusual number of meteors are then developed. So I kept watch most 

 of the time from 8:30 to near midnight to see what for a show of meteors would 

 be visible. In the three hours near eighty "falling stars" were seen. Making 

 allowance for intervals used in recording the time, position, magnitude, ex. I 

 have no doubt that one hundred or more were developed in the region observed, 

 which was the southeastern part of the sky, including probably one-eighth of the 

 entire hemisphere. It seems hkely that they were as numerous in one part of the 

 sky as another. Then, perhaps, eight hundred meteors — all large enough to be 

 easily seen — made their appearance in the upper, or visible, half of the heavens. 

 Applying this calculation to the other half — below my horizon — we get 1,600 for 

 the probable number of meteors developed in three hours. 



It is beheved that the earth was about two days in passing through the meteor 

 stream. But the outer parts of it are probably thinner than the central — which I 

 suppose was the part traversed by the earth during the loth. But we»will aim to 

 stay within bounds, and suppose the earth to occupy twenty-four hours — say 

 from noon of I oth to noon of nth — in traversing the main, or average part of 

 the meteoric body. Then we have eight times the number in three hours, equal 

 to 12,800 for the number of meteors which the earth encounters while going 

 through this body of meteoric matter. It may be observed that in twenty-four 

 hours the earth travels 1,600,000 miles. 



Some fifteen or more of the meteors observed on the loth were as bright as 

 stars of the first magnitude, all having trails of light behind them. A few indeed 

 were much brighter — nearly as bright as Venus ; making their sudden appearance 

 and flashy trails almost startling. The direction of their motion was generally 

 south to southwest. One or two, however, moved in the opposite direction, and 

 soon after another had gone south. Two or three moved across the other tracks 

 nearly at right angles. The motion of nearly all was quite rapid, and the paths 



