6. The "Throttle Valve" of the main steam-pipe, which, by means of the
handle, is opened or closed at pleasure, the power of the steam and the
progress of the carriage being thereby regulated from 1 to 10 or 20
miles per hour.
7. The Tank for Water, running from end to end, and the full breadth of
the carriage; it will contain 60 gallons of water.