LONGITUDE OF COBOURG, ONTARIO. 59 



Combination op Results. 

 September 6th. 

 Chronogi-ajjh comparison gives: — 



h. in, s. h. m. s. 



Chronometer 20 55 31.24 when clock was 20 40 00.00 



s. s. ra. s. s. 



Chro. alow.. .20. 802— .005= 20.857 clock slow 4 57.231 — .010 4 57.221 



20 55 52.097 20 50 57.221 



20 50 57.221 



Difference = 4 54.876 



September 8th. 



Chronograph comparison gives : — 



Chronometer 21 24 30.20 when clock was 21 15 00.00 



Chro slow.... 23. 910 — 006 = 23.904 clock slow. .4 58. 740 +.010= 4 58.756 



21 24 54.104 21 19 58.750 

 21 19 58.756 



Difference = 4 55.348 



Mean of the two differences 4 55.112 



Personal equation .093 



4 55.205 

 Reduction to dome of Faraday Hall .089 



4 55.116 



An allowance for transmission time would increase this by a small amount ; we may, ], ^^ g 



therefore, take the longitude of the dome of Faraday Hall as 4 55.15 



loss than tlie transit instrument at Toronto, which is 5 17 34.65 W. 



The longitude of tlie dome of the Faraday Hall, as determined by j, ^ g 



these observations, is, therefore 5 12 39.5 West of Greenwich. 



