Shooting Stars of August 9 and 10, 1840. 329 



direction of their paths was similar to the general course on the 

 9th. The evening of the 6th was overcast. The evenings of 

 the 7th and 8th were mostly clear, yet I made no special obser- 

 vation, preferring to watch in the morning, bat, unfortunately, 

 the sky was too much clouded both on the mornings of the 8th 

 and 9th. The night of the 9th was beautifully clear and serene. 

 Mr. Francis Bradley, Mr. J. T. Hotchkiss and myself, watched 

 most of the night, each confining his attention to a quarter of the 

 heavens, the southern being neglected during the moon's pres- 

 ence. At 3 A. M. (10th) Mr. Amos Hill (who with his son had 

 been in company with us the whole time) took charge of the 

 southern quadrant. Our station was on the summit of the Hos- 

 pital, which commands an unobstructed view of the heavens. 

 The following is a statement of our observations ; the meteors 

 being reckoned in that quadrant in which they started. 

 1. Number of Meteors noted. 



818 

 Three observers can not generally detect more than three 

 fourths of the meteors which would be seen by four ; and four 

 observers are certainly insufficient to secure the whole. Brilliant 

 meteors may undoubtedly be seen through half the heavens, but 

 we have often found that many of the fainter class pass unnoti- 

 ced if the observer is not looking within ten degrees of their 

 path. Until a few minutes before setting, the moon's light must 

 have concealed from our view about half the meteors which ac- 

 tually fell. Taking these circumstances into account, it can not 

 be reasonably doubted that if the moon had been absent, more 

 than 1500 shooting stars 'would have been visible at this place 

 between 10 P. M. of the 9th and 4 A. M. of the 10th. The aver- 

 age number of these meteors visible to four observers during the 

 like space of time at ordinary seasons may be taken at about 250, 



