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

64by the numbers here given, and when full, works out as follows —:For 40ft. cylinder, divide -r 120 atmospheres by 3,= 40'„ 20 ft. ,, „ 120 ,, X 6, = 20„ 15 ft- " " 120 „ X 8, = 15„ 10 ft. ,, ,,120 ,, X 12, = 10This may appear perhaps confusing at first, when once grasped it isvery simple. Example: —A 40 feet cylinder is taken, the contents ofwhich are not known, the indicator gauge stops at 80 atmospheres.80 -=- 3 = 26, (26 feet).The contents of a cylinder may be roughly estimated, by weighing thecylinder when empty and again when filled, and keep a record of thedifference. As a rule 10 feet go to the pound.A few precautions may be necessary to the novice : do not under anyconsideration oil any connection with the cylinder especially the valvepin, or use soap, or white lead if there should be a leakage. Wipe outthe seat of the coupling before connecting the regulator. This ismost important especially with the inside thread valves, as thedust often collects here in no small quantities If the valve isthought to leak at the orifice, place a little soap suds or saliva across thetop, and if there is an escape of gas it will make itself known by thebubbles it will force up. Should the valve pin be too hard to turn, havea key with a long arm, it will give a good leverage. It is not necessaryto turn the key more than once round to open cylinder, nothing isgained by continuing this motion as more gas cannot be forced throughthe valve, should the cylinder be full and the key turned many times, itwill force the pin out, and as it will come out with force, the consequenceswould be very unpleasant.Should the valve be one as supplied by Erin's Company, it will be sureto want a little tightening up as it becomes worn round the seat of the pin,to do this turn the key on slightly, at the same time turn the nut whichholds same the reverse way, with a pair of gas plyers or a spanner, agood leverage is wanted for this.This form of valve generally has the thread inside the collar whichprotects it from injury in travelling. The valve of a cylinder shouldbe used carefully, its structure being very delicate and easily damaged.It is now customary to make the hydrogen thread on cylinders andregulators left-handed, so that it is compulsory to use only the properregulator and fitting for each gas, it was rather confusing at first, but isan excellent plan, as there can be no possible mistaking the gases.