18 



well caved in for sixty feet above it and completely covered it. Six 

 weeks were passed in clearing the well and getting ont the broken 

 sinker. Next the water used in the engine, in consequence of large 

 quantities of lime and sand held in suspension soon coated the flues of 

 the boiler with a very hard scale and caused them to leak badly. It 

 was therefore necessary to take down the engine and reflue it entirely, 

 inserting manheads for cleaning. Very shortly after we again resumed 

 boring we passed into alternating thin strata of blue slate and flint 

 limestone, the most difficult strata we have yet encountered. Water 

 pours in at several places in the well in considerable streams, and 

 very soon washes away the slate, which is soft, but leaves the sharp 

 jagged edges of the hard limestone fully exposed; in a very little 

 while the wooden rods working through these strata would be cut in 

 two; iron rods were substituted, but they were soon bent so badly, by 

 coming into violent contact Avith the sharp limestone, as to be useless; 

 I therefore was obliged either to diminish the bore by inserting smaller 

 tubing, or sink the large tubing to the bottom. The exceeding diffi- 

 culty of the last plan induced me to prefer the former, and the hole was 

 lined with three-inch copper tubing from the lower to the upper thin 

 layer of limestone. Unfortunately, very soon after effecting this, the 

 iron slips broke immediately beneath the bottom of the copper tube, 

 and so spread apart that they could not be withdrawn through the 

 tube ; it was therefore necessary first to take out the tube — a work of 

 difficulty. It was all gotten out except nine feet of the lower part, 

 which pulled off", and had to be bored and speared up. The boring 

 up and pumping out of the copper tube was completed yesterday, 

 and the head of the broken slips is now exposed so that they can be 

 withdrawn. 



Since our arrival at this camp we have been thus embarrassed by 

 difficulties and breakages, altogether due to a most peculiar, difficult, 

 and uncommon formation of great and hitherto unknown thickness. 

 The strata are so distinctively marked that they can be easily recog- 

 nised in their outcrop between the Pecos river and the Guadalupe 

 mountains; and we have reached the stratum of slate exposed plainly 

 at the head of Delaware creek, about forty feet above the issue of the 

 powerful fresh and mineral springs which form the sources of that 

 stream. 



The winter here has also greatly incommoded us from inadequate 

 protection of the men from unusually inclement weather for this re- 

 gion, and there were many days during the severe northers, incident 

 to this country, in which it was impossible to work. The spring is 

 now fairly open, and I trust we shall soon be able to finish this work, 

 as I am altogether certain that the water is but a little way below us. 



I am, sir, respectfully, your obedient servant, 



JOHN POPE, 

 Captain Top^l Engineers. 



Capt. A. A. Humphreys, Corps TopH Engineers, 



Washington, D. 6'., in charge of Office ExpV s and Surveys. 



