The sciopticon manual, explaining lantern projections in general, and the sciopticon apparatus in particular; Including magic lantern attachments, ... mechanical movements, etc

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1877 Excerpt: ...of potash (one pound) and the black oxide of manganese (four ounces). See that none of the mixture falls upon the cylinder head, so as to prevent the cap fitting closely down. Now rub a little tallow on the cap to make a smooth joint, replace it so that the marks on the cylinder and on the cap will coincide, and screw the nuts down tight; then screw on the gauge and open the valve. Allow the cylinder to remain on the fire until the gas has come off, which will be indicated by the rise of the colored fluid in the gauge. The gas from one pound of chlorate of potash will raise the fluid to within three-fourths of an inch to an inch of the top of the tube. The cylinder ought not to be made red hot in any part. When the gas has come off, set the cylinder away to cool; and after it has become eold, shut the valve, remove the gauge, and screw on the nipple. It is now ready for use at any time, but can remain in the cylinder for months, if not required sooner. "When the gas is all used up, shut the valve, and let it stay closed until you wish to make a new lot. This will keep the cylinder dry and obviate the necessity of drying over the fire before recharging. Then, when you wish to make fresh gas, unscrew and remove the cap, tapping the end of the wrench with a hammer if the nuts are hard to start; take a piece of wood, sharpened at one end, insert it in the cylinder, and break up the residuum by a few vigorous blows; pour it out and recharge without either washing or drying. "To operate the cylinder for hydrogen, unscrew the cap as before, put in two pounds of scrap zinc, and add a mixture of sulphuric acid and water (four pounds of acid and four quarts of water). This mixture should be cold when poured into the cylinder. As soon as the liquid is poured...