The Art of projection and complete magic lantern ... - Yesterday Image

84been considerably augmented since the introduction, or we should say ofthe more general use of cylinders of high pressure.It was the custom ofthe makers of pressure gauges, for steam and hydraulic purposes, to testthem with oil, and it was almost impossible to dry them out, the resultwas the bursting or exploding of the gauges as previously mentioned inthe forepart of this chapter. We have had the experience and we nowknow the cause, and we may venture to say that we shall not hear anymore of gauges bursting through this cause, as every possible care istaken to avoid contamination of the gauge tube and connection with oil.^Vater being the sole mode for testing, and it entirely remains with us tocarry out the principles already laid down, and under no considerationever allow oil or any lubricant to be applied to any portion of the connectionsor gas cylinders, and always to dust the seatings of connections,to reduce the risk of any foreign substance being blown into the gaugeor regulator, and especially to turn the gas on from the cylinder valveslowly. We have left, till last, an important item, viz. :—To remove theglass face from the gauge before using, a moveable glass front is, wethink, most essential, as it is the glass that does the damage if it shouldburst ; it is as well not to stand over the guage when turning on the gas,it is just as easy to hold it away from the body, and as much leveragemay be put on the key. A\'ith a view to minimising the risk of the gasrushing in too suddenly, a plug between the valve and the tube in gaugeisintroduced in some gauges now being made, no matter how suddenlythe gas is turned on, the plug valve relieves the pressure from the gaugetube, allowing only a minimum quantity of gas to pass, from the time thevalve is opened until the indicator is at rest, is about 30 seconds ; too muchfaith should not be put in these arrangements, as it is so easy to regulatethe flow from the valve of the cylinder. In our initial experience ofgauges, the same gauge did duty for both oxygen and hydrogen gases,and the force with which the gas rushed into the gauge was never considered,and there are, no doubt, hundreds of other lanternists who havedone the same, and yet have never had an accident. " Forewarned,forearmed,'"' use only a distinctly marked gauge for each gas, markingeach gauge back and front with a good sized H or O as most gauges(when not marked for feet for a given size bottle) indicate lbs. pressure{black figures) and atmospheres {red figures) with the aid of the redfigures and the following table, the quantity of gas in a cylinder isaccurately ascertained.