The steam rising from this spring--the Giant's Caldron--can be seen for many miles in every direction. The movements of Muddy Geyser were closely watched for twenty-four hours by Mr. Campbell Carrington, who was specially detailed for that duty by Dr. Hayden. His observations began about nine o'clock A.M., July 1st. Then the pool was calm. Shortly after, he heard the loud, hissing noise of escaping steam. Hurrying to the geyser, he saw a wave about three feet in height rise and die away to the left; three similar waves followed in quick succession. Their dense columns of steam burst up to the height of twenty feet, with a dull, heavy explosion, the action continuing for fifteen minutes, when the spring ceased flowing as suddenly as it had begun. The average height of the flowing was about fifteen feet, though some of the jets reached fully thirty feet. Five minutes after the eruption the pool measured twenty-five feet in circumference and three in depth, where before it was a hundred feet in circumference and eleven in depth. Ten minutes later the mud began to rise slowly in the pool. This continued for a little over three hours, when the spring began to boil near the centre. The ebullition gradually increased in violence for twenty minutes, then it suddenly stopped, and the eruption began as at first. This rising, falling, and overflowing took place eight times in twenty-four hours. The following table shows the time of the observed flowings and their length: "First flowing, 9.20 A.M. to 9.35 A.M.; length, 15 minutes. "Second flowing, 1.30 P.M. to 1.50 P.M.; length, 20 minutes. "Third flowing, 5 P.M. to 5.15 P.M.; length, 15 minutes. "Fourth flowing, 8.30 P.M. to 8.50 P.M.; length, 20 minutes. "Fifth flowing, 12.30 P.M. to 12.45 P.M.; length, 15 minutes. "Sixth flowing, 4 A.M. to 4.15 A.M.; length, 15 minutes. "Seventh flowing, 7.30 A.M. to 7.45 A.M.; length, 15 minutes. "Eighth flowing, 11 A.M. to 11.10 A.M.; length, 10 minutes. "Total length of time, 26 hours. Aggregate time of flowing, three hours and 15 minutes. Average length of flowings, 15 minutes and 37 and one half seconds." CHAPTER X. YELLOWSTONE LAKE. "Such a vision," exclaims the sober-minded chief of the Geological Survey, "is worth a lifetime; and only _one_ of such marvellous beauty will ever greet human eyes."