Glass Identification - Post here for all ID requests > Glass
lead glass
Frank:
Lead glass was developed at Nijmegen in Holland by John Odacio Formica (Italian), John Baptiste da Costa and Jean Guillaume Reinier.
Da Costa later 1673 set up a glassworks in England he shared his knowledge with Ravenscroft and two workers went to Scotland and produced lead glass from 1687. Formica wento Ireland where lead glass was made in Dublin in 1675 under Lloyd's patent. Reinier went to Sweden.
See Peter Francis, The Development of Lead Glass, Apollo February 2000, pages 47 to 53
From those earliest times it was known as Flint Glass when it was distinguished from Crystall that did not contain lead. The white lead being derived from Flint.
Fuhrman Glass:
Just to"muddy the waters" a little. Mckearin in his book American Glass states that in 1611 Neri wrote in his treatise on glass: stated that glass of lead was known to few but was the fairest and noblest glass of all others at that day made in the furnace. Neri"s Art of Glass was supposedly translated into English in 1662.
Does anyone have a copy of Neri's Art of Glass? I don't think I've ever seen a copy of it.Tenn. Tom
Only thorough way to absolutely determine if it is a lead based glass is with a mass spectrometer. Corning labs offer a service that they will run an analysis of any glass you send to them if you're willing to pay the fee.
I think weight can sometimes fool you if it is a barium based glass as it can be very heavy as well.
Frank:
Still trying to find an affordable copy of that but I was aware it mentioned the use of lead. I had not noted the translation date and that certainly ties in well with what Francis says is the 'development' as opposed to the discovery. The speed of take up is interesting too, I am often surprised at the speed which ideas travelled in those days. Presumably as Reinier went to Sweden that country also started producing lead glass at that time?
krsilber:
--- Quote from: Fuhrman Glass on July 11, 2008, 11:10:19 PM ---Just to"muddy the waters" a little. Mckearin in his book American Glass states that in 1611 Neri wrote in his treatise on glass: stated that glass of lead was known to few but was the fairest and noblest glass of all others at that day made in the furnace. Neri"s Art of Glass was supposedly translated into English in 1662.
--- End quote ---
I've just been reading Guttery's From Broad Glass to Cut Crystal, The History of the Stourbridge Glass Industry (1956). He talks about Neri's book (translated, BTW, but Christopher Merret) and a couple paragraphs later there's a quote, "Glass of Lead, beyond doubt the fairest and noblest Glass; if this Glass were as tough as Crystal it would surpass it in beauty...a perticuler sort of Christaline Glasse resembling Rock Christall not formerly exercised or used in this Kingdome" (italics mine). This quotation doesn't have a reference, but strikes me as quite similar to the one Tom talks about, so is it Neri? And what Kingdom? The next sentence in Guttery says, "But glass of lead was not something new; the Lorrainers here had used oxide of lead as a flux in attempts to obtain a more readily fusible mixture when they were forced to cover their pots on the first use of coal as fuel....The technical difficulties which caused Ananias Henzey such troube in Ireland in the sixteen-fifties were probably encountered in attempts to make a successful lead glass." And "W.A. Thorpe, historian of English glass-maiking, asserts very confidently that it was an invention ín the stricter sense of the word, the result of an attempt conceived deliberately and carried out experimentally to provide a sound commercial substitute for rock crystal.'"
...SO, it appears lead was used in a variety of places before Ravenscroft did his thing, but he went down in history for perfecting a high-lead glass.
The Neri bit still confuses me - were they using it in Italy by 1611? It sure would be nice to have that book. Must cost a small fortune.
...I wrote something like this in the Flint Glass thread, but will repeat it here. "The white lead being derived from Flint." Has this been substantiated? It seems unlikely, since flint didn't have much in the way of impurities, it's HARD, and not all that heavy. Would lead have been extracted from it before use, and if not, it seems like it would be hard to control the amount added.
Another quote from Guttery: "At first Ravenscroft had used flints, but the glass which he handed over to English glass-makers when he made no attempt to renew his patent in 1681, was glass of lead." I don't understand why they would be mutually exclusive, doesn't make sense. Flint was just another source of silica. In 1696 John Houghton wrote, "Our glassmen for making the best flint glass use instead of powdered flints a very fine white sand," which could be interpreted as saying that the glassmen used flint still for not-best glass.
Frank:
That might be misleading as the usage of flint seems to have been applied to more than one type of stone. That part of the info is unclear so best ignored.
The record should change so that Ravenscroft was the first patentee in England. Patents were different in those days to what we understand today and were basically gotten via the king/privy council - no doubt in exchange for a fee. If someone came along with more money or more influence the first patent could be annulled and someone else issued with it. Seems to have gone on a lot. So in Scotland the patent went to Sir James Standsfield and Sir Phillip Lloyd in Ireland 1675. Certainly in Scotland the patentee was very close to the king. I have my feelers out for a copy of the Francis's research... so if anyone has a copy. Also if someone knows if there is a picture or text of any of the patents to see if any of the names of the trio appear on it.
Anyway it will be a while before I come back to this as it is just a side issue of my current project.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version