=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_). This is then carried to an auxiliary heated furnace, which has a wide opening emitting great heat, and by resting the pontil upon a convenient support and rotating it quickly the action of centrifugal force and heat causes the glass to spread out at the opening, which becomes larger and larger until the glass finally opens out into a flat circular disc of fairly even thickness throughout, with the pontil still at the centre, forming a bullion point or slight swelling, due to the knob of glass used in affixing it (_d_). Next, the workman, keeping the disc in rotation, brings it away from the furnace and allows the metal to stiffen and set by cooling, when it is carried to the annealing oven and detached from the pontil. The discs are then stacked up for annealing. When annealed, these are afterwards cut across in sections or squares of convenient size by using a glass cutter’s diamond. [Illustration: FOUR STAGES IN CROWN GLASS-MAKING ] It is evident that the centre portion, containing the bullion point or bull’s eye, is useless for plain window glazing, but occasionally these are sought after by glass decorators for use in coloured leaded lights for door panels, etc. =Sheet Glass= is made in the form of thin, walled, hollow cylinders of glass, which are split along their length and round the cap and then opened out by heat and allowed to uncurl until each sheet lies out flat. The workman gathers a sufficiency of glass upon his blow-iron by repeated gatherings, and marvers it into a ball about as big as one’s head. This is blown out (_a_) and widened by rotating the blow-iron until he gets a mushroom shape (_b_), with a heavier bulk of glass at the extremity than at the sides. [Illustration: SIX STAGES IN SHEET GLASS-MAKING ] This extra thickness of glass at the extremity of the bulb tends to lengthen the bulb of glass as he swings it in a pendulum fashion, and by blowing and swinging it alternately he gets an extended form (_c_).