236 GEOLOGICAL SURVEY OP THE TERRITORIES. 



Suddenly this ceased, and, at the same instant. Fountain commenced 

 playing, throwing a body of water, some 10 feet in diameter, though 

 mostly broken into drops, to constantly varying heights of from 5 to over 

 40 feet. This continued for about thirty minutes, and then ceased rather 

 abruptly ; as suddenly, the steam jet commenced again. About twenty 

 minutes later it ceased again, and a small pool, a few yards from 

 Fountain, which had been empty before the latter's eruption, but par- 

 tially filled by its overflow, immediately began to boil and to spit water 

 from 5 to 10 feet high, and continued intermittently for a half hour or 

 more. During its periods of moderate boiling, the steam-jet opened 

 again, but ceased when the boiling became more violent. Other vents 

 in the neighborhood seemed to have some slight sympathy with these. 

 Similar facts were noted elsewhere. Thus, in the Upper Basin, Grand 

 Geyser has only a small pool, and erupts only at long intervals. Close 

 by its side. Turban Geyser is almost constantly disturbed, and has fre- 

 quent small jettings of Irom 5 to 20 feet ; but, when Grand, without giv- 

 ing any warning, sprang suddenly into its magnificent eruption, nearly 

 200 feet in height, Turban seemed startled into more violent action, 

 reaching 70 or 80 feet, and rising and falling synchronously with Grand. 

 Giant stands, with another good-sized mound, upon a broad platform on 

 the river-bank. As 1 first saw it, water was spirting, intermittently, to 

 heights varying from C inches to 20 feet, from some fifteen or twenty small 

 vents on various parts of this platform. When the two large vents began 

 to show activity, though boiling to only small elevations, these little ones 

 became quiet. When Fan Geyser was in full eruption, its partner, 30 

 yards off, was steaming gently. Fan stopped for a moment, and its 

 partner fairly roared with a rush of steam, which stopped as soon as Fan 

 opened again. Yet they are not in full sympathy ; for, on another oc- 

 casion, Fan was steaming or boiling very gently, while its partner was 

 boiling furiously, and throwing water 5 or 10 feet high, but with quiet 

 intervals, during which Fan showed no access of force. (Under such 

 circumstances, one is inclined to question whether Fan's partner may 

 not possibly serve as the vent for two distinct geyser-tubes.) The three 

 pools which surround Giantess lost much water by her eruption, but were 

 not drained as low as the bottom of her pit when that was empty. 



In many cases, however, vents almost side by side show not the least 

 sympathy. About 200 feet east of the Steady Geyser, in the Lower 

 Basin, which constantly spouts from 5 to 20 feet, Young Hopeful spirts 

 from 2 to 10 feet high for from sixty-five to eighty seconds, with quiet 

 intervals of about the same length. About GO feet from it, another small 

 vent S[)irts from G inches to 2 feet, for from thirty to forty seconds, with 

 intervals of from forty-five to sixty seconds. Here is evidently no 

 sympathy. 



The deposits made by the springs and geysers vary greatly. Where 

 the flow is gentle, the deposition generally takes place in thin lamince, 

 of thickness varying from that of a sheet of paper to a quarter inch. 

 Though, as previously stated, this is so compact as to be dissolved with 

 difliculty from below, yet its thin laminae are readily separated and 

 broken by frost, and form a very peculiar tine gravel, immediately rec- 

 ognized after having been once seen, which has served to indicate the 

 former location of hot springs over broad areas which give no other 

 evidence of such vents ever having existed. In the small pools 

 which surround many of the geysers, we frequently find great numbers 

 of apparently water-worn pebbles; but, upon breaking them, we find 

 their structure concentric, and it becomes evident that they have grown 

 by constant surface-accretions, while the frequent agitation of the pools, 



