The water within the lock chamber proper, beyond the entrance chamber, is brought to the level of that in the approach, the gates toward the vessel are opened, the fender chain is lowered, and the locomotives maneuver the vessel into the chamber and bring it to rest. The gates are then closed, the water raised or lowered, as the case may be, to the level of that in the next chamber, the gates at the other end are opened, and the vessel moved forward. Three such steps are made at Gatun, two at Miraflores, and one at Pedro Miguel. When the vessel has passed into the approach chamber at the end of the locks, the lines from the towing locomotives on the side wall are first cast off, then those from the locomotives on the approach wall, and the vessel clears under its own power. Towing is not ordinarily required in any part of the canal, except in the locks, for steam or motor vessels. Tug service for sailing ships or vessels without motive power is at the rate of $15 per hour. If the channel in the cut has been disturbed by a slide, tugs may be used to handle vessels past the narrow places, but in such cases there is no charge for the service to vessels of less than 15,000 gross tonnage. * * * * * What is a Geyser? The famous geyser shown in the illustration is called “Old Faithful” because of the clock-like regularity of its eruptions. For over twenty years it has been spouting at average intervals of sixty-five minutes. Geysers were first observed in Iceland and the name, therefore, comes from that language, being derived from the word “geysa,” meaning “to gush” or “rush forth.” That is just what they do. There are really three different kinds of geysers; one which throws up hot water, either continually or, like “Old Faithful,” at intervals; one which simply emits steam and no water and one which is a sort of a hot-water cistern. The “Grand Geyser” at Firehole Basin in Yellowstone Park is the most magnificent natural fountain in the whole world. The “Great Geyser” and the “New Geyser” are the most remarkable ones in Iceland, where there are about a hundred altogether. The basin of the former is about seventy feet in diameter, and at times it throws up a column of hot water to the height of from eighty to two hundred feet in the air.