Needle No. 1. 



Needle No. 2. 



71° 11'.20 



71° 17'.25 



19.00 



14.00 



71 15.10 



71 15 .62 



leedles, 



71 15.36 



MADE IN THE UNITED STATES. 319 



During the observations of this day at Baltimore, Professor John Locke, of 

 Cincinnati, made at the same time, and places, and with his own dipping in- 

 strument, consentaneous observations. 



IV. Magnetic Dip at Washington city, D. C. Latitude 38° 53' 31" N.; Longitude IT V 24" W. 



Place of observation the eastern garden of the capitol, at about the middle 

 of the central avenue. 



Date. Hour. 



1841, June 5, 7 — 10, A. M. Observed dip, Poles direct, 



" " " Poles reversed, 



Mean dip. 

 Mean dip of both needles, 



The observations of this day were made conjointly with Major J. D. Graham, 

 he observing with an instrument of Gambey's construction, and I with my 

 Robinson's. — Weather fine, light north-west wind, light clouds near the hori- 

 zon. The temperature during the observations from 72° to 84°. 



V. Magnetic Dip at Washington city, D, C. 

 Place of observation the same as the preceding. 



Date. Hour. Needle No. 1. Needle No. 2. 



1841, July 15, l—H, A. M. Observed dip, Poles direct, 71° 18'.75 71° 10'.50 



" " " Poles reversed, 9 .50 21 .25 



Mean dip, 71 14.12 71 15.87 



Mean dip of both needles, 71 15 .00 



Remarks. — Weather cloudy, calm and sultry. Last night, a heavy storm 

 between 9 and 11 o'clock. The temperature during the observations from 

 79° to 81°. 



VI. Magnetic Dip at Washington city, D. C. 

 Place of observation the same as the preceding. 



Date. Hour. 



1841, July 16, 61—91, A. M. Observed dip, Poles direct, 



" " " Poles reversed. 



Mean dip, 

 Mean dip of both needles, 



RemarJcs. — Sky clear, N. W. wind, tolerably strong. The temperature 

 during the observations from 73° to 76°. 



VIII. — 4 F 



Needle No. 1. 



Needle No. 2. 



71° ll'.OO 



71° 17'.75 



16.75 



9.75 



71 13.87 



71 13.75 



needles, 



71 13.81 



