On an Improvement in Pressure Gauges

Abstract

The writer’s attention has for some time been directed to devising some means of increasing the employer’s control over his engine driver, and it has led him to the improvement which he hereafter proposes to describe. In laying this subject before you, it may be desirable here to state that he conceives it, and proposes to treat it, as more particularly applying to the employment of high pressure steam, and to engines of this class, perhaps, more especially the locomotive and steam boats, he selects as examples, because they are, when at work, so little under the eye of the employer. It is a well known fact amongst individuals conversant with the working of the class of engine mentioned, that it is too frequent a practice (and perhaps a great temptation if not controlled,) for engine drivers—in the locomotive for instance, when behind time, or when ascending heavy gradients over loaded; and, in the case of steam boats, when contending against head winds, or running in competition with other boats—to screw down the safety valves much beyond the limited pressure, thereby in all probability endangering the boiler under his charge, or to say the least, injuring it in a greater or lesser degree, without leaving any immediate trace behind to convict him of his recklessness. To obviate this, the writer proposed to the Patentee of a very recent Pressure Gauge to add to the ordinary working index or pointer of the dial another index, which, for better comprehension ...