176 



Miscellanies. 



deeming it unnecessary to add any remarks of my own, farther than to 

 express my entire confidence in the accuracy of his determinations. 



Micrometric Measurements taken hy E. P. Mason. 



During the progress of the eclipse, frequent measures were taken of 

 the distances of the cusps, and the corresponding instants of observation 

 were accurately noted. The instrument with which these were obtained 

 was an achromatic object-glass micrometer, of Dollond's construction, 

 attached to a 7 ft. Reflector, the value of whose scale had been determined 

 by frequent comparisons with an accurate sextant in terrestrial measures, 

 and by observations on stars of the Ast. Soc. Catalogue. The following 

 are the distances obtained : 



A mean of 4 measures, in a direction about 15° or 20° inclined to the 

 horizon, and 20m. previous to the instant of first contact, gave for the 

 sun's diameter 31' 53.7". These were, however, taken amidst the hurry 

 of preparation for the eclipse, and were too few in number to be a stand- 

 ard for the subsequent measures. The following horizontal diameters 

 may be considered more determinate, and will serve to show the confi- 

 dence which may be placed in the measures of the cusps : 



