17 



Extract from a letter from. Captain A. A. Humphreys, Topographical 

 Engineers, in charge of Offi,ce of Explorations and Surveys, dated 

 April 14, 1858. 



"Sir : Your reports from the camp on the Pecos river of the 26th 

 and 28th of February were duly received, and submitted to the Sec- 

 retary of War. 



"In consideration of the unexpected difKculties and consequent, 

 unavoidable delays that have occurred in your work upon the artesian 

 well near the Pecos, the Secretary of War directs that, upon the 

 completion of that well, instead of proceeding to complete the artesian 

 well west of the Rio Grande, you will omit that work and continue 

 the experiment of sinking artesian wells on the plains or basins east 

 of the Rio Grande, as indicated in the fifth paragraph of your instruc- 

 tions of the 5th of May last." 



Camp on Pecos Rivee, May 1, 1858. 



Sir : I submit the following report of operations in the prosecu- 

 tion of the experiment of sinking an artesian well on the ' ' Llano 

 Estacado." 



The boring is done by means of oak poles, 1| inches in diameter, 

 in 16 feet sections joined in twos by heavy iron straps. Each boring 

 rod is therefore 32 feet long with a male screw at one end and a female 

 screw at the other, both having very strong and heavy threads. 

 The drill has a straight edge of 3| inches, and is attached to an iron 

 rod 30 feet long and 1^ inch in diameter. To the upper end of this 

 rod (or sinker) is attached a pair of iron slips, having a play of 16 

 inches (the fall of the drill) and to these are screwed on the wooden 

 poles, up to the surface. The upper end of the poles is attached by 

 a moveable chain to a spring beam worked by steam, and (boring at 

 the usual speed) the drill falls fifty-five times in a minute. The borings 

 are pumped out by a sand pump of copper, 9 feet long, which works 

 with a rope passing round a drum attached to the steam engine. The 

 hole is pumped out on an average once in 2^ hours of boring. 



The difficulties we have encountered have resulted from the peculiar 

 soft and crumbling strata of variegated marls and clays, which are of 

 an uncommon thickness, not, I believe, to be found elsewhere within the 

 range of geological examination. It has been necessary in this case 

 to line the well with tubing from the surface, and as combining strength 

 and lightness wrought iron tubing ^V o^ ^^^ ^^^^^^ thick was brought out 

 with the expedition. 



The first difficulty met with was in sinking the tubing to a depth of 

 81 feet lower than it was left last year (810 ft.). Although with the 

 under cutting drills it was easy to enlarge the bore below the tube so 

 as to admit the latter to pass down freely, yet the friction along the 

 sides resulting from the crumbling and falling in of loose slightly cohe 

 rent strata around it, was so great that it required driving as heavily 

 as it would bear to force it down. Next the iron sinker broke oft" in 

 the middle and before anything coulJ be put down to withdraw it the 

 2 H 



