Vv, 



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16 • Ex. Doc. No. 41. 



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and halted for tlie day near running water; the grass was all burn- 

 ed dry, aftd not a green sprig to be seen. Three buttes were passed 

 of singular appea^rance; some idea of which will be given by the 

 sketch. They were composed of lime-stone, and were garn^hed 

 at their bases with nodules of carbonate of lime, like those described • 

 yesterday. A part of our road was on the dry bed of a river, paved 

 with argillaceous lime-stone, containing, now and then, the impres- 

 sion of oyster shells very distinctly. The valley in -which we are 

 now encamped presents the appearance of a crater, being surround- 

 ed with buttes capped with stunted cedar, (juniperus Virginianus 

 The stratification, however, appears regular, and to correspond on 

 different sides of the valley. 



The growth of to-day was similar to that fouad on the plains 

 yesterday, to which may be added an evergreen and a magnificent 

 cactus three feet high, with round limbs shaped Hke a rope, three, 

 and a half inches in diameter, branching at right, angles. It is said 

 the Mexicans make hedges of it. 



Colonel Doniphan's regiment passed bur camp about 4, p. m. 

 The water was in pools, charged with veg£table matter and salt. 

 The formation of the adjacent hills was distinct- first, a stratum 

 of lime-stone, ten feet thick, then hard sand-stone, withamoilites 

 and a variety of other shells, &c., overlaying blue marl. From the 

 sides of the hills protruded geodes, with crystallized lime-stone, and 

 the ground was everywhere strewed with detached pieces of ferru- 

 ginous sand-stone- On these hills we found cedar growino^, very 

 -stunted; Missouri flaxj several varieties of wild currantsj a very 

 stunted growth of plumsj moss and cacti in great variety, but di- 

 minutive. 



The latitude of this camp, by nine observations on Polaris, out 

 of the meridian, is 37^ 44' 56'^ 



The longitude derived from the chronometer^ by an estimate of 

 the local time derived from eight measurements of the double alti- 

 tude of arcturus on the west, and seven of alpha aquilee in the east, 

 is 6^, 547/1. 06.75. 



The barometer reading indicates a height above the sea of 4 761 

 feet. 



August 4.— The road wound through the yalley of the Tirapas. 

 The soil, being impregnated \yith lime, rendered the dust, which 

 rose in dense columns, distressing. 



. Dwarfed cedar skirted the road on each side. The strata of hills 

 on either side of the valley -were the same as described yesterday; 

 but the ferruginous nodules and blocks of sand-stone were more 

 frequent. , , • 



Thirteen miles' march brought us to the crossing of the Timpas. 

 The only water we found there was in a hole 40 feet in diameter, 

 into which the men rushed with great eagerness, disturbing the 

 vegetable deposit formed on its surface, and thereby rendering it 

 unfit for use. ^S^ine miles farther on we came to "the hole in the 

 rock" — a large hole filled with stagnant, though drinkable, water. 



We saw at times, during the day, a few antelopes, rabbits, wild 



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