536 American Philosophical Society. 



" At Urbana, lat. 40° 03' N., long. 83° 44' W., March 30, 1838. 

 the cUp was found = 71° 29'-94. 



" At Columbus, the seat of government of Ohio, lat. 39" 57' N., 

 Ion"-. 83" W., April 3, 1838, the dip was found = 71" 04'-875. 



'^The interest of this paper is much increased by the circum- 

 stance that no accurate experiments on the intensity and dip of the 

 needle have heretofore been made in the United States, west of the 

 Alleghany mountains. 



" The Committee conclude their report, by recommending that 

 Professor Locke's communication be printed in the Society's Trans- 

 actions." 



Sept. 21, 1838. — The Committee on the solar eclipse of the 18th 

 of September, made a report in part, comprising the observations 

 made at Philadelphia, the principal results of which are as follows : 



The observations made at Philadelphia are fifteen in number. 

 A list of observers, telescopes, &c. is given in the following table. 

 The correction in the third column is to be added algebraically to 

 the latitude of the place of observation, to obtain that of the State- 

 House, + 39° 56' 58". The correction in the fourth column is 

 likewise to be added to the local longitude in time, to obtain that of 

 the State-House. -5''0"'39•2^ 



A. Beginning. Professor Johnson noticed dark indentations for 

 eight seconds after the first disturbance of the limb. 



B. Arch of faint light, with speck or brush in centre, round the 

 moon's limb beyond the cusps ; brush or blaze in centre, between 

 cusps, extending outwards about two digits. One cusp broken at 

 end presenting a bright bead. 



C. Arch of light much increased in brightness, the brush or 

 blaze, at first in the centre, now extends from cusp to cusp ; radia- 



