GEYSERS. 1 bres: 
the Yellowstone, the first part of the geyser eruption is somewhat differ- 
ent. Perhaps the most familiar geyser of this type is Old Faithful, the 
one geyser in the Yellowstone that is sure not to disappoint the visitor. 
Though surpassed by many of its neighbors in the heightand magnitude 
of its eruptions, it holds a front rank for beauty and gracefulness. Pre- 
viously heralded by loud rumblings, with spasmodic outbursts of 10 to 
20 feet in height that mark abortive attempts to send up its steaming 
pillar, the white column is finally thrown upwards with a loud roar, and 
mounts at once to a height that seems hundreds of feet as we gaze upon 
it. For two, or even three minutes, the column maintains a height 
which measurements show to vary from 90 feet up to 150 feet, with oc. 
casional steeple-shaped jets rising still higher, the jets ever varying and 
giving off great rolling cloudsof steam; then the jets gradually decrease 
in altitude, and in five minutes the eruption is over, the tube apparently 
empty, and emitting occasional puffs of steam for a few minutes longer. 
During the eruption the water falls in heavy masses about the vent, 
filling the basins that adorn the mound, and flowing off in yellow and 
orange-colored waterways, while the finer spray drifts off with the 
breeze and falls upon the neighboring sinter slopes. It is impossible 
to measure the amount of water thrown out, since it runs off in a num- 
ber of directions in shallow rills that lead either to the sandy terrace 
near by or to the river. If however we assume that the column of 
steam and water is one-third water, a fair assumption, the estimated 
discharge is 3,000 barrels at each eruption. 
Comparing Old Faithful with its Iceland prototype we find consider- 
able difference in the behavior of the two vents during the interval 
between eruptions. The former, like Strokr, has no bowl or basin, and 
the geyser throat or tube is partly filled with water, which is in con- 
stant and energetic ebullition, while the geyser is inactive. The tube 
and bowl of “ Geyser” are, on the contrary, filled with comparatively 
cool water. In each case, however, the eruption is preceded by an 
overflow from the geyser tube, in the case of Strokr and Old Faithful, 
as jets of 10 feet to 25 feet in height; in ‘‘ Geyser” by a filling of the 
bowl and successive overflows, accompanied by the noise of condens- 
ing steam bubbles, a simmering of the water in the tube. Such pre- 
liminary actions are significant when we consider the theory of geyser 
action. 
Theories of geyser action.—The intermittent spouting of geysers was 
long a riddle to scientific men, for although several theories seemed 
each to offer a satisfactory explanation of the eruptions of ‘ Gey- 
ser,” they supposed conditions unlikely to occur in many vents. The 
investigations of Bunsen, and of Descloizeaux, who spent two weeks 
studying the Iceland fountains, resulted in the announcement of a 
theory of geyser action which, with slight modifications, has satisfied 
all requirements and is to-day generally accepted as the true explana- 
