Gauge, WATER

Device to indicate the height of fluid inside of containing ve els. Simple floats are much used, connected to a pointer traversing a scale. For steam boilers the gla gauge is nearly universal, a strong tube being connected to the shell at the bottom below the lowest water-line and at the top above the highest. The water can be seen in the gla tube to be at the level Water Gauge. at which it stands inside the shell. Fixtures at the top and bottom of the gla tube make it convenient to replace the tube when nece ary, and in these fixtures may be placed automatic valves to close should the gla break in use. Closure or stoppage of the lower connection to the tube is one serious defect of this type. Besides the tube, gauge or try-cocks are used. Three or four small cocks are placed one over the other, with the central one at the normal water level, so that when one is opened it will draw off a sample of what is inside the boiler at that level. This indication is infallible, and these cocks are universal as a water gauge. Other water gauges are in the form of alarms. In one of these a tube is let into the top of a boiler below the proper water line, on the outer end is a whistle. When the water falls below the end of the pipe the steam sounds the whistle.