602 APPENDICES. 
tain supplies of provisions; and in ten days after the recommencement 
of the work, the survey of the Gila will be completed. In the mean 
time, until the arrival of Mr. Bartlett, who is supposed to be at Guay- 
mas, or, while awaiting other means of procuring supplies for our re- 
turn, myself and assistants Sire actively employed in completing our 
observations and plotting the notes of the survey. 
I remain, Sir, very respectfully, 
Your obedient servant, 
A. W. WHIPPLE, 
Lt. U. S. Topographical Engrs. 
To Brey. Lr. Cox. J. D. Granam, U.S. T.E. 
Principal Astronomer, etc., 
U.S. B. Commission 
E. 
Colonel J. D. Graham to the Hon. Alex, H. H. Stuart, Seere- 
tary of the Interior, in reference to the Survey of the 
Head Waters of the Gulf of California and the River 
Colorado, by Lieutenant I. G. Strain, U. S. Navy. 
Wasutneron, December 31, 1850. 
The Honorable the Secretary of the Department of the Interior 
having referred to me (for my views of the measures therein suggested) 
the letter of Lieutenant I. G. Strain, of the navy, of the 31st of October 
last, and the papers accompanying it, I have the honor to state that I 
have perused them all with attention, and that I feel obliged to give it 
as my opinion (which I do with all deference), that the measures sug 
gested by Lieutenant Strain have no relation whatever to the survey and 
demarkation of the boundary under the Treaty of Guadalupe Hidalgo; 
and that they ought not in any way to be connected therewith. I have 
made a careful calculation of the length of boundary line to be sur- 
veyed and marked by suitable monuments, and find it to be about one 
thousand six hundred miles, independent of the lateral surveys that will 
be requisite, in order to determine the true line of boundary, should 
