By permission of Melin & Co.
VERTICAL CRACKING-OFF MACHINE
The Glass Workers’ Union consider that the introduction of machinery deprives men of their independence and right to work, but as yet the glass blowers have been always fully occupied with useful work about the factories in which such machines have been introduced, so it cannot be said that they have been forced to be idle.
The advantages possessed by these automatic machines in their larger output at so much less cost compared with hand labour is the great factor in inducing their adoption; and in these days of progress and competition such machines enable the glass manufacturers to cope with the increasing demand and go far towards bringing a factory up to date and making it well equipped.
Manufacturers should certainly turn their attention to these mechanical methods, as their use is quite general on the Continent and in America, and by their use the metal can be worked out of the pots or tanks much more quickly, increasing considerably the turnout or capacity of the furnace against the fuel consumption. Much of the glassware imported into this country is composed of such articles as would have been manipulated by machines, and, unless a similar method of manufacturing them is adopted here, we cannot hope to compete with other countries in supplying our own needs. In the writer’s opinion, it is mainly due to the adoption of machinery for producing glassware that the continental people have been enabled to undersell us in our own market, and English manufacturers could produce at a much cheaper rate if they would only adopt similar methods of manufacture and the gas-fired furnaces as used abroad.
CHAPTER XII
CROWN, SHEET, AND PLATE GLASS
The glass used in windows may be either crown, sheet, or plate.
Crown Glass is made in the form of circular flat discs about 4 ft. in diameter. The workman, by repeated gatherings, collects sufficient glass on the end of his blow-iron until he has a mass approximately 10 or 14 lb. in weight, which he marvers into a pear-shaped lump by rotating the hot glass in the hollow of a wooden block. He then blows the glass into a spherical bulb (a), which, by quick rotation, is widened and assumes a mushroom shape (b). Another workman attaches a pontil to the outer centre of this bulb by welding it on with a small portion of hot metal.
The blow-iron is then detached by wetting and chilling the glass near to the blow pipe, which breaks away, leaving an opening in the bulb where it has become detached (c).