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

"67valves are of little use as a means of safety, and are an encumbrance,checking the flow of gas.OXYGEN (Brin's Patent),now generally used in cylinders is the pure gas. The common air ispurified and dried by passing through lime and caustic soda, andpumped into retorts, charged with barium oxide, which under a heat of1,400 Fall., has the chemical properties, for absorbing the oxygenfrom the air, the nitrogen and other products being conveyed away.The air is pumped into the retorts at 10 lbs. pressure, the pumpsare then automatically reversed and the oxygen is then sucked fromthe barium oxide, the process thus using no chemicals whatever, andbecomes simply mechanical. Oxygen manufactured under this processhas the advantage of being free from chlorine, which is not the case withoxygen manufactured from potasse chlorate, it is the chlorine thatdestroys the rubber in gas bags, and causes the green deposit in thetubes and taps of jets. Brin's oxygen when first introduced six yearsago differed materiall)', the quantity of nitrogen being left in, beingconsiderable, and thus made a great difference in the illuminatingpower, these difficulties have now long been overcome and the averagequality of oxygen is93 per cent.TESTING AND FILLING CYLINDERS.We cannot give a better description than an account of our interviewwith the able manager of Brin's oxygen works, Mr. Keith S. Murray,which took place at their factory, and goes to prove that the burstingof a cylinder, or mixing of the gases, is an impossibility, and thatthe public stand at no risk whatever, and considering that the makers ofthe cylinders have previously tested them to two tons pressure on thesquare inch, there is not much fear of a cylinder coming to grief in thehands of the public." Do you test every cylinder sent you, Mr. Murray ? ""Yes, cylinders are tested by us to double their working pressure,viz. 1 1 tons. Our test is of course an hydraulic one."" Have you ever had a cylinder burst after it has left your factory ?" Not that I have ever heard of, and we are supplying now over amillion and a half feet annually, compressed into cylinders, which meansthat many thousands of bottles pass through our hands."" Do you ever burst cylinders in testing ? ""All cylinders are filled by us to one standard pressure, viz. 120atmospheres; and as I have already said they are first tested by us withE2