250 AT THE COCO-MARICOPA AND 
their mistake, they all burst into a hearty laugh, which 
was joined in by the rest as they came up. Assem- 
bling around our two Maricopas, they learnt the par- 
ticulars of our visit to the Salinas. They then all 
wheeled around; and while a portion acted as our 
escort to their villages, others fell behind and brought 
up the rear, so that our entry was that of a grand 
cavalcade. At 8 o'clock, we reached our place of 
encampment, having travelled fourteen miles. 
In the afternoon, Lieutenant Whipple and his party 
arrived. They had completed the survey of the Gila, 
a labor at this season of the year, with the heat at from 
100 to 120 degrees Fahrenheit, attended with no small 
difficulty. 
June 6th. As the notes of this survey, and the 
accompanying astronomical observations, had been 
obtained with great labor and some suffering. I felt 
unwilling to expose them to the risk of being lost in 
a journey across the continent; and, accordingly, 
determined to remain here a few days longer, to give 
Lieutenant Whipple an opportunity to duplicate them 
with the view of sending them back by a messenger 
to Major Heintzelman, at Fort Yuma, to be forwarded 
by him to the Secretary of the Interior at Washing- 
ton. 
A brisk trade was carried on to-day with the Coco- 
Maricopas for corn, beans, meal, pinole, and squashes, as 
well as for the various articles of their manufacture, 
such as pottery, cotton blankets, baskets, &c. I gave 
the trading department into Mr. Thurber’s hands, find- 
ing it would be better managed by one person. He 
fitted up his tent for the purpose and made such a dis- 
