In and About the City; New Way of Making Glass; glass tank furnaces introduced at Brookfield

IN AND ABOUT THE CITY

NEW WAY OF MAKING GLASS

A FURNACE WITHOUT CRUCIBLES AND

ITS BENEFIT TO BLOWERS

After many years of the use in glass works of crucibles in the preparing of glass for the pipes of the blower, a German named Ferrari has found a way of doing without them by the use of a new furnace, which now reaches its highest exposition in the Bushwick Glass Works of William Brookfield, situated on Grand Street, Brooklyn. There, every day, Sundays, of course, excepted, a lot of glassblowers may be seen exemplifying the new system, which is, or may become, a revolutionizer in glass blowing. It is a simple method, and one which it would seem ought to have presented itself to glass blowers or glass bottle makers years ago. Given a certain mixture of sand, soda ash, and lime, and the glass blower is happy, but the glassmaker is not necessarily so. He wants to reduce the cost of production, as well as increase the normal value of the material. So in Mr. Brookfield's establishment, where have been made three-fourths of the telegraph insulators used in this country, they are now trying the new system. Under the old fashioned method a crucible of molder's clay capable of holding a ton of glass mixture was made. The crucible itself was heated for 36 or 48 hours, carried on an iron frame called a "goat" to a furnace, in which, heated to about 3,000° Fahrenheit, the glass material was dumped. There the crucible and its contents sizzled and boiled until the following morning. When the blowers truck their long, polished blowing tubes into the white-hot mass, and from that drew the material from which they blew bottles. So soon as the mass in the glass blowers crucible was exhausted so soon as he had finished his work.

Under the new method a man may blow glass from one years end to the other if he possess the wind and energy. The supply of material is inexhaustible. Crucibles are abolished. The mixture necessary for common green glass is dumped into a great tank, which takes the place of the five, six, or eight crucibles in the old-fashioned furnace. When the mixture has reached the necessary liquid condition, and is molten glass, it runs through a small flue into another compartment, and into this the workman sticks the end of his tube and picks up a quantity of material of which to blow a bottle. There are no crucibles to annoy him, or cheat him out of a day's work, as the breaking of one may do at any time, and meanwhile fresh glass mixture is being heated into molten glass at the other end of the furnace.

As a matter of economy, the most important facts to the maker are that the making of crucibles is abolished: so virtually is the occupation of the "master shearers," the men who watch the crucibles and place them in position for the blowers to draw from. Then the blowing engines and all their accessories necessary to the old system are done away with, natural draught taking their place.   Under the old process it required a ton of coal to heat a ton of glass to the necessary consistency to be blown. In the new process it only requires three-quarters of a ton to heat the same amount of glass. Then, too, under the new the quantities of soda ash and of lime-the two expensive materials-are materially reduced. The product is not injured by the new process, so far as careful experiments show, but on the contrary, the glass as it comes from the furnace to the pipe of the blower, is denser and tougher, and when it leaves the annealing furnace is certainly much more lustrous. Experiments which Mr. Brookfield and his Superintendent, Mr. Pease, have made show that the expense of running two furnaces of 13 tons productive capacity, 72 percent greater in the cost of labor, for attendance, and of fuel alone. The economy of the new system is virtually a combination of the Siemens gas furnace system and the best features of the old pot or crucible system, involving the least expense with the best and highest productive capacity.