16 



boiler of the steam-engine, forms a hard, solid coating around the 

 flues in the course of a very few days, and occasions leakage in the 

 boiler sufficient to prevent the raising of steam, I have been obliged 

 in consequence to reflue the boiler throughout, and to make man- 

 heads enough to enable a man to clean it thoroughly at least once 

 every six days. This has occupied several weeks. 



The peculiarity of the formations is another source of great diffi- 

 culty, which much time and labor are necessary to overcome. For a 

 hundred feet above the bottom of the well there are consecutive 

 strata of soft slate and of hard flinty limestone in thin layers. The 

 slate is washed away by the agitation of the water, leaving the sharp 

 edges of the limestone exposed so as to cut in two in a very few mo- 

 ments the wooden poles, and to bend iron substitutes so that they are 

 rendered useless. 



There is great difficulty in sinking the tube arising from the soft, 

 crumbling character ot the whole formation from the surface down. 



Although the bottom of the tube is perfectly free and loose, the 

 friction along the sides is so great that the driving necessary to move 

 it is sufficient to crush the upper end of it and to tear out the screw 

 threads below. 



The tube we are using is the iron (wrought) which you sent from 

 Philadelphia last year. 



We are now endeavoring to sink the tube to the bottom with fair 

 proispect of success, though it will be a work requiring time. 



I have little doubt we are in close vicinity to the water, as the 

 formations are peculiar and readily identified with their out-crop, 

 about forty feet above tlie head springs, Delaware creek. 



I have reduced my party to the smallest possible limits, and shall 

 be able to maintain it in the field at least to July 1, 1859. 



I send herewith topographical and geological sketches and sections 

 exhibiting in detail all possible information concerning the vicinity 

 of the well. The geological section from the Guadalupe mountains, 

 exhibits as you will observe some different features from those here- 

 tofore sent. I have satisfied myself for sufficient reasons that the 

 Pecos flows througli a valley occasioned by upheavals along lines both 

 east and west, and is not a valley of denudation. The dip of the 

 strata from the Gaudalupe mountains is not continuous across the 

 "Llano Estacado" witli a constant descent, but rises east of the Pecos 

 in a gentle undulation without fracture to the summit of the plain, at 

 an altitude of six hundred feet above the river, and a distance of 

 about thirty-five miles from it. 



The geological section will exhibit plainly what 1 have stated. 



I will of course prosecute this work Avith all vigor and perseverance, 

 and I by no means despair of completing the work here in time to 

 accomplish a larfre portion of what was proposed when the expedi- 

 tion took the field. 



