Polished plate is a type of hand-blown glass. It is produced by casting glass onto a table and then subsequently grinding and polishing the glass. This was originally done by hand, and then later by machine. It was an expensive process requiring a large capital investment.
Other methods of producing hand-blown window glass included: broad sheet, blown plate, crown glass and cylinder blown sheet. These methods of manufacture lasted at least until the end of the 19th Century. The early 20th Century marks the move away from hand-blown to machine manufactured glass such as rolled plate, machine drawn cylinder sheet, flat drawn sheet, single and twin ground polished plate and float glass.
The Frenchman, Louis Lucas de Nehou, in 1688, in conjunction with A. Thevart, succeeded in perfecting the process of casting plate-glass. Mirror plates previous to the invention had been made from blown "sheet" glass, and were consequently very limited in size. De Nehou's process of rolling molten glass poured on an iron table rendered the manufacture of very large plates possible.
In 1773 English polished plate (by the French process) was produced at Ravenhead.
By 1800 a steam engine was used to carry out the grinding and polishing of the cast glass.
Famous quotes containing the words polished, plate and/or glass:
“Some poems are for holidays only. They are polished and sweet, but it is the sweetness of sugar, and not such as toil gives to sour bread. The breath with which the poet utters his verse must be that by which he lives.”
—Henry David Thoreau (1817–1862)
“Then he rang the bell and ordered a ham sandwich. When the maid placed the plate on the table, he deliberately looked away but as soon as the door had shut, he grabbed the sandwich with both hands, immediately soiled his fingers and chin with the hanging margin of fat and, grunting greedily, began to much.”
—Vladimir Nabokov (1899–1977)
“Thou didst create the night, but I made the lamp.
Thou didst create clay, but I made the cup.
Thou didst create the deserts, mountains and forests,
I produced the orchards, gardens and groves.
It is I who made the glass out of stone,
And it is I who turn a poison into an antidote.”
—Muhammad, Sir Iqbal (1873–1938)