APPENDIX. 



289 



Geneva, June 23, 1854. 



Dear Sir : I inclose you herewith, on another page, the results 

 of my father's observations of latitude and longitude, so far as I 

 have been able to collect them. His calculations indicate great 

 pains and labor to obtain accurate results. They are too volu- 

 minous to copy. 1 trust, however, that I have been as particular 

 as was necessary in the inclosed memoranda. If anything else is 

 wanting, I should like you to inform me. 



I am, sir, with great respect. 



Your obedient servant, 



MALCOLM DOUGLASS. 



Mean 

 latitude 



of 

 Detroit 



Bestdfs of Observations for Latitude and Longitude during the Ex- 

 pedition of 1820. By David B. Douglass, Capt. Engineers, 

 U.S.A. 



By 3 sets of observations at Cunning- - 

 ham's Island, 1819, and reduced by 

 exact measurement on the Bound- 

 ary Bay 

 By 1 set of observations at Gibraltar 

 Island (Put-in Bay), taken, like the 

 ■\ preceding, in 1819, and reduced as |- 42° 19' 20" 

 before 

 By 1 set of observations taken on 

 Sugar Island, and reduced as before 

 By mean results of 2 sets of observa- 

 tions—May 17 and 21, 1820 

 By mean observation, Sept. 29, 1820- 

 Mean longitude of Detroit, by 6 sets of observa- 

 tions, May 17 and 19, 1820 . . . . 82 39 00 

 Latitudeof Presque Isle, Lake Huron, June 5, 1820 45 19 45 

 Latitude of Mackinaw, by 4 sets of observations, 

 June 7 and 11, 1820, by meridian observations, 



Sept. 12, 1820 45 50 54 



Height of Fort Holmes. From the water 

 to the brow of the hill near Eobin- 

 19 



