INITIAL POINT ON THE RIO COLORADO. 113 



Gila." la consequence of the thick growth of timher along the river, this was effected on the 

 sand plain until near the terminal point. The timber on the hottom-land there is nearly two 

 miles in width, and lines of sight for the theodolite had to he cut through it to approach the 

 river. This obstructio» delayed the work^some time, and numerous dust-storms also impeded 

 its progress, preventing the possibility of using any instrument for several days at a time. 



On the 14th February, 1855, we moved the main camp from opposite Fort Yuma, in order to 

 be more in the vicinity of our work ; a beautiful mezquite grove near a laguna of fresh water 

 was selected. This spot was close to the edge of the sand plain, and the nearest desirable one 

 to the terminal point of the triangulation, about two miles distant in a direct line. It is the 

 site of Fitzgerald's battle-ground^ twenty-two miles, by the road, below Fort Yuma. We were 

 here joined by our escort, company I, 1st artillery, officered by First Lieutenant (now captain) 

 Francis E. Patterson, and Second Lieutenant Henry W. Closson, 



By the 4th of March the triangulation and survey were all completed, an observatory erected 

 near the initial point of the new azimuth line, (running eastward to the intersection of the 

 111th meridian west of Greenwich, with the parallel 31° 20^ north latitude,) and astronomical 

 observations with the transit and zenith instrument commenced. Our lucky stars did not, how- 

 ever, prove to be in the ascendency; first, clouds obscured them, and then the rising waters of 

 the Colorado did not leave us long undisturbed. There came a freshet from the Gila, far up in 

 the mountains, causing the Colorado to rise very slowly — so slowly that we anticipated no dan- 

 ger. The sloughs began to fill up between the observatory and the camp ; the men bridged 

 them, and still we hoped to see the water recede before forcing us to move. Day after day 

 it continued to advance upon us until the night of the 19th, when the instrnments were 

 packed and moved to a higher point, five hundred yards distant. By this time the water had 

 entered the observatory, and to reach it we were compelled to wade waist-deep for nearly the 

 whole of that distance. An extract from my notes of the 20th says: ^^ Compelled again to 

 move the instruments and carry them up to camp ; every slough is filled, all rapidly rising, and 

 several swimming deep ; rafts tuilt to transport the men over tbem ; all the men in water up to 

 their breasts, and instruments only kept dry hy heing carried on their heads. About noon all 

 safely in camp ; water within fifty feet of it, and everybody getting ready to leave. At sunset 

 the river still continues rising, and gradually approaches camp, but so slowly that we are still 

 in doubt. At 2 o'clock a. m,, decided to take to the sand-hills ; the long roll was beaten, the 

 camp struck, the train loaded, and all moved on the high plain. Behind us lay a desert of 

 sand forty miles across, and in front was spread a sheet of water several miles in breadth. From 

 fifteen hundred feet the Colorado had widened to at least five miles." 



After being forced from our position, the river commenced falling back into its old channel. 



The bottom-land had become so boggy, it was many days before we were able to reach our ob- 



- servatory. In the mean time, that portion of the Mexican commission appointed to co-operate 



with me arrived. The party was composed of Don Francisco Jimenez, 1st engineer, in charge, 



assisted by Seuores Manual Aleman and Augustine Diaz, 2d engineers. Captain Hilarion Garcia 



i 



and Lieutenant Romero were the officers of the escort. 



Having already made much progress in the work, Mr. Jimenez consented to adopt the initial 

 point fixed by me. He also accepted its longitude as determined by my triangulation. Having 

 succeeded at length in reaching the river, we were both enabled to commence observing for lati- 

 tude ou the night of the 1st of April. After ten nights of successive observations a mean of 

 the results of each party was taken as the final determination. The latitude of this initial 



Yol. I 15 



