So2 surfaces during the operation, cutting open the cylinder longitudinally, reheating it, and flattening it out in a sheet which is then annealed. Prior to 1903 window glass was made entirely by hand, and there is still about 40 per cent. of the production of the United States manufactured by this method. A brief description may therefore be of interest and aid in making clear the difficulties involved in devising apparatus to do the work mechanically. The tool used is the blower's pipe, about 5 feet long, with a mouthpiece on one end, and on the other the bell-shaped wrought “pipe head.' The workmen are the blower, gatherer and snapper, or blower's helper, the three men constituting a “shop.” The gatherer starts the operation by dipping the glass which adheres and forms a small ball. He blows through pipe head, which has been previously heated, sufficiently to expel the soft glass from the interior and form a small bubble in the ball. The glass is then cooled to the proper stiffness, more glass gathered and the operation repeated until there is sufficient glass to yield a cylinder of the desired size. For an ordinary cylinder the gatherer usually gatherR five minutes. The lump, which is in a state of rather stiff plasticity, is then carried to the “blower's block,' an iron mould set in water to keep it from becoming too hot, and lined with charcoal to prevent the glass from being marked by contact with the iron. By turning the ball in the block, blowing air into the lump through the pipe and drawing it up towards him, the blower so manipulates the operation as to form a pear-shaped ball, the upper part of which has the diameter and thickness of the cylinder to be produced, the bottom containing a thick mass of glass that has now become quite stiff. The ball is now re-heated in a “blow furnace' and wheri soft enough the blower swings it out in a 'swing hole' alongside the blow furnace. The weight of the glass elongates the cylinder, ANATHBANDHU. Volume 1. LSLSLSLSTSLSL LSLSLSeMLSSSMSq q AALLLLASMS AAASAAA SLLLL LLLLLLLLSLLLSLSLLLSLSLSLSLSLSLSiSLSL S Maulauan NMANN diameter by intermittently blowing air into it through the pipe. The re-heating and swinning out is repeated until the glass in the closed end of the cylinder is of the same thick time blowing into the pipe and keeping the air confined by hold. ing his thumb ness as the other f \ pourts. This clos- Ο Δ' Ε' the mouth ed end is now ex- piece. The glass posed to the heat N in the end softof the blow fur- ': ens, and the heat nace, the work- :Ñ at the same time man at the same ଝୁ); expands the air in 置 - عمر قمر - "بیر" སྔ་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་ཀ་སུ་སུ་་ཅུ་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་་ 穷 ތިރިވި&{{ 劾 ܦ2-- -ܧ を効。 “፰m፡ 凸 శ Z) س ዏ...” : - گل &ല്പ- Š . . . -ն.` ՀՀ a" DOUBE REVERSBI, OT AND FURN ACE. NVo other form of receptacle for the molten glass eram equal it for higs output and economical operation. the cylinder, which finally bursts out through the end. The open end is heated still further and swung ont into the swing hole in such manner as to make it cylindrical to the end. The pipe is removed by touching a cold iron to the glass just below the pipe head, and the pear-shaped cap removed by stretching a thread of hot glass around the cylinder, allowing it to remain until a heated streak is formed, and touching this streak with a cold iron causes the cap to snap off. The cylinder is split by passing a hot iron back and forth through the cylinder to produce a similar line of heat and touching it at one end with a cold iron, which results in a and the blower keeps it distended to proper straight crack from end to end.
