263 



pole. Mr. Herrick,* at New Haven, who had previously invited attention 

 to this period, in the United States, on the same evening, found this point 

 farther north than in the November shower ; but determined nothing farther. 

 In 1838, these meteors were seen by Mr. Kreil, at the Milan Observatory, 

 but no radiant point was deduced. In the United States, however, Professor 

 Forshey, from 65 meteors seen in one hour, August 9th, at Rock Island, Iowa, 

 concluded the radiant to be situate within a circle of 2° radius, centering in the 

 sword cluster of Perseus. In 1839, Mr. Herrick,t with others, at New Haven, 

 found the radiant point to be near the sword cluster, on the 9th and 10th, 

 being nearly stationary. On the 10th, at 13A., they found it to be near 

 6 Persei. 



Mr. Forshey, in 1839, August 10th and 11th, at St. Louis, again noticed the 

 radiant point in the same position as in 1838. But the position of this point 

 or rather of the point of convergence of their apparent paths, has been com- 

 puted with great precision from the observations at Berlin, August 9th, 10th 

 and 11th, and at Konigsberg, August 10th and 11th. The mode of observa- 

 tion adopted at the European observatories has been to mark on a map the 

 points of origin and disappearance, and, subsequently, to compute, by Mr. 

 Erman's formulae, the common point of convergence. As the August meteors 

 become visible chiefly in the northern zones, it was thought that greater pre- 

 cision would be attained by nothing, besides the point of origin and disappear- 

 ance, also the part of Perseus or Cassiopea, intersected by the apparent path 

 of the conformable meteors traced backwards through one of these constella- 

 tions. The following table gives the point of convergence thus deduced from 

 three separate groups of observations at Philadelphia, together with the posi- 

 tion of this point, as determined at the European observatories, and the pro- 

 bable error of a single result, and of the final result computed in the usual 

 manner. The general agreement in the positions will be seen. The small- 

 ness of the probable errors of the Philadelphia results is attributed to the 

 method employed in observing; by which a greater proportion of the meteors 

 seen was marked unconformable, and excluded from the general estimate. 



August Meteors. 



Apparent 

 R. A. of 



Apparent 

 Dec. of 



No. of 





wl 



Place of Observation 

 and date. 



point of 

 conver- 

 gence. 



the point 

 of conver- 

 gence. 



Observa- 

 tions. 



-a -5 

 o <o 



J- <*-* 

 Pn o 



_2 £ 



"I S 



Cw o 



1837. Berlin, Aug. 10 



21718 



— 57°26 



46 



o 

 ±20.1 



±2°96 



,« Breslaw, „ 



221.76 



— 51.41 



200 



±19.5 



±1.38 



1839. Berlin, 9 



224.86 



— 50.18 



50 



±11.9 



±1.68 



10 



'223.88 



— 52.39 



48 



±13 3 



±1.92 



11 



218.45 



— 51.05 



43 



±13 5 



±2.06 



,, Konigsberg, 10 



214.85 



— 55.59 



75 



±21.0 



±2.42 



11 



215.11 



— 55.29 



74 



±17.4 



±2.02 



1840. Phila.9<110h57m 



216.14 



— 55.76 



12 



± 2.3 



±0.67 



„ 9 13 4 



214.71 



— 55.43 



15 



± 4.1 



±1.05 



„ 9 15 G 



219.25 



— 55.12 



29 



± 1.2 



±0.22 



* Silliman's Journal, Vol. 33, p. 176 and 359. 

 t Ibid, Vol. 37, p. 328. 



