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:
“Mining today is an affair of mathematics, of finance, of the latest in engineering skill. Cautious men behind polished desks in San Francisco figure out in advance the amount of metal to a cubic yard, the number of yards washed a day, the cost of each operation. They have no need of grubstakes.”
—Merle Colby, U.S. public relief program (1935-1943)
“Our press is certainly bankrupt in the “thrill of awe”Motherwise reverence: reverence for nickel plate and brummagem. Let us sincerely hope that this fact will remain a fact forever; for to my mind a discriminating irreverence is the creator and protector of human liberty.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“We all drew on the comfort which is given out by the major works of Mozart, which is as real and material as the warmth given up by a glass of brandy.”
—Rebecca West (1892–1983)