EL PASO. 
177 
As soon as the initial point of the boundary line, 
where the Rio Grande intersects the southern boundary 
of New Mexico, had been agreed upon by the Joint 
Commission, Lieutenant Whipple entered upon his 
duties as Chief Astronomer, to determine the position 
of the point on the Earth’s surface, taking with him 
such assistants from the engineers and surveyors, etc., 
as he required. A second party, first under J. H. 
Prioleau, Esq., and subsequently under Thomas Thomp- 
son, Esq., entered the field in January, 1851, and 
commenced the survey of the Rio Grande at San 
Eleazario, which they continued up to the initial point 
at 32^ 22' north latitude. I also set a small party at 
work to make a survey of the town of El Paso and 
district adjacent, including the mountains, the pass, 
etc., embraced in a circuit of ten miles. These were 
all the parties 1 could place upon the survey, until the 
arrival of the chief astronomer. Brevet Lieutenant 
Colonel J. B. Graham, who had been appointed to that 
place in October last, but had not yet arrived. Conse- 
quently a large number of the engineers, with their 
assistants, could not be occupied ; and this I greatly 
regretted, as the best season for field operations was 
now passing away. 
1 had given employment, for a few weeks, to John 
Bull, Esq., one of the first assistant engineers, with his 
party, in making a reconnoissance of the country 
between the Rio Grande and the Gila, via the Copper 
Mines of New Mexico, a district over part of which 
the boundary would run. Mr. Bull explored a new 
and more direct route from Dona Ana to the Copper 
Mines than that usually travelled ; and examined the 
VOL. I. — 12 
