170 



THE AUBIFEEOUS GRAVELS OF THE SIEEEA NEVADA. 



eight feet in the course of 150 feet and then to pitch off suddenly to the northeast. And for the 

 ne°xt three or four hundred feet no bed-rock has been found, because, there being no chance for a 

 cheap drainage into Missouri Canon, there has been no attempt made to reach bottom by shaft 

 sinking. On the farther side of the mine the bed-rock rises almost precipitously, so that its highest 

 point (near the northeastern bank of the mine) lias an altitude, as estimated by the hand-level with 

 reference to known objects, of fully 3,040 feet. In the central part of the mine, according to Mr. 

 Hussey, " blue gravel'' was uncovered in digging to connect with the sluices and boxes at the out- 

 let/ A section across this part of the gravel is given on Plate F (Fig. 5), — the vertical as well as 

 the horizontal scale being two hundred feet to the inch. Beyond this high rock Mr. Hussey thinks 

 there is still another channel, with a southerly or southeasterly course, but of this I was not 

 fully convinced. There is, however, in the next small excavation to the north, a comb of bed-rock, 

 dipping both to the east and west and apparently a continuation of the high rock in Ilussey's 

 Mine. To the east of this comb the bed-rock has not yet been struck, which circumstance adds, 

 it is true, some weight to the theory of the additional channel. Still, there may be no real con- 

 nection between the two exposed masses of rock, or the latter may be nothing more than a high 



place, like an island in the stream. 



Keeping along in nearly the same direction, the next point of bed-rock measured, beyond Hus- 

 sey's, was in the bottom of the mines on Darling's Hill, near the western bank. Its altitude we 

 determined to be 3,064 feet. Other rock was seen at about the same elevation, at a number of 

 points on Darling's and Boston hills, but it was by no means clear that there was any dip to the 

 east. The general slope of the country from Darling's Hill is to the west, and considerable slate 

 is seen between the mines on the hill and those at Eed Dog, as is seen by following the line of 

 the Bunker Hill ditch from near the outlet of Ilussey's Mine. For one or two hundred feet from 

 Hussey's slate-rock is seen ; but it soon disappears, and the ditch is dug in gravel for nearly a 

 quarter of a mile. At the westerly end of the hill, about a quarter of a mile east of the town of 

 Eed Dog, slate-rock was met again in the bottom of the ditch, and its altitude determined to be 

 2,908 feet, — almost identical with that at the head of Hussey's sluices. From this point on (witl 

 the exception of perhaps a hundred feet of gravel near by) the ditch runs entirely in slate around 

 the north side of Darling's Hill and the head of Arkansas Canon, to where the water is taken 



down to the Bunker Hill Mine. 



The altitude of the bed-rock at Eed Dog has been already given as 2,621 feet. The same result 

 was also obtained for the bed-rock at Independence Hill on the opposite side of Arkansas Canon 

 from Eed Dog. The rock not being very even at either place, an error of two or three feet could 

 easily be made in fixing upon the point to be measured, so that these two results are to be re- 

 garded not so much as deciding anything about the direction of the channel between the two 

 places, as corroborating the general statement that there is a fall of about thirty feet from the 

 bottom of the Cozzens and Garber shaft to the bed-rock at Eed Dog. 



The highest point of the Independence Hill gravel is nearly 200 feet above the bed-rock, being 

 about on a level with a small gravelly knoll, at the east end of the high flume, the altitude of 

 which was determined to be 2,821 feet. On the northern side of Independence Hill I also deter 

 mined the altitude of a point on the rim — 



* 



j lorn _tobe 2,723 feet. 



The observation at the bed-rock of Williams' mine on Bunker Hill — by which the altitude was 

 made to be 2,632 feet — was taken at a later date than the others, when the nearest station barom- 

 eter was at Colfax, and is consequently not to be trusted quite so implicitly as the others in the 

 series, though there is no probability of any great errors. Both at Independence and Bunker hills 

 the gravel shows the same succession of blue and red as is seen at Eed Dog and below You Bet. 



These are the principal points where observations for altitude of bed-rock were taken within the 

 You Bet and Eed Dog districts. For convenience of comparison, the results, so far as they shed 



o 



light upon the question of direction of channel, may be brought together as follows : 



i 



at the outlet of a small claim discharging into Green- 



