Early manufacture of glass involved single sheets of glass manufactured by a craftsman by blowing through a tube. Generally the further back in history you go, the wavier the glass is. Wavy glass is the cool-looking glass commonly found in older window panes, doors, and furniture built prior to the early s. Early glass also has tiny bubbles called seeds. As craftsmen improved their methods over time, the wave and distortion became less apparent. As a result, glass produced in the s tends to have more distortion than glass produced in the s. In the early s, increasing industrial advances led to machine-produced glass. This glass, while less wavy, still had imperfections and was widely used in the United States cities in the early s. Crown Glass was used in Europe starting in the mids.
Craig J Kennedy , K. Robin Murdoch, Susanna Kirk. Characterization of archaeological and in situ Scottish window glass. Robin; Kirk, Susanna. The elemental composition of the glass provides information regarding the materials used and, subsequently, an approximate range of dates of manufacture.
Crown glass was an early type of window glass. In this process, glass was blown into a “crown” Artistic and historic techniques. Beadmaking · Blowing · Blown plate · Broad sheet · Caneworking · Cased glass; Crown glass; Cylinder blown sheet · Engraving.
It is a non-destructive analytical technique that provides a wealth of information, including element mapping. Decorated windows have been a feature of English churches for over years, depicting scenes from the Bible, the lives of saints, royalty, heraldry and benefactors. In some cases the glass remains in its original windows, but more often it has been moved at least once and many windows have been destroyed.
This makes it difficult or impossible to reconstruct the windows and identify the decorations. On many fragments the decoration is completely obscured. There are over fragments of glass, generally in poor condition. Some fragments are so corroded that they are completely opaque. Backscattered X-radiography was also tried, but as the examples show, there was much greater success with micro-XRF. Comparison of techniques used to examine the glass fragments.
Using an integrated motorised platform, the surfaces of objects can be scanned, mapping the distribution of various elements. Paint has a different elemental composition to the underlying glass. So far over fragments from the collection have been scanned using micro-XRF. The scans show that the painted designs on many are closely related, making it possible to reconstruct the original designs and identify the subjects. Identifying the types of paints and pigments also helps to date the fragments.
The history of antique window glass goes back to a time just before the turn of the first century AD. Phoenicians along the Syrian-Palestinian coast developed a technique of glassblowing that allowed for a variety of shapes of hollow glass items. Spreading throughout Germany, Italy, France, and Switzerland as a result of the rise of the Roman Empire, glassmaking flourished and the Romans began using it for architectural purposes. It wasn’t until the 11th century that the mouth-blown cylinder technique of making sheet glass for windows was first developed in Germany and later adopted by the Venetians.
Cylinder Glass and Crown Glass are two types of authentic, mouth-blown antique window glass typically found in historical structures in the United States.
Our story begins more than 35 years ago. She launches Graboyes Commercial Window Company, a glazing company that will become an unmatched leader in the Philadelphia area. Graboyes Commercial celebrates 25 years in business and is listed as one of Inc. Founder Terry Graboyes decides to partially retire, selling the majority of the company to Tricia and John Scott.
The move to The Navy Yard is designed to further unify all of the main staples of the company from sales and design to engineering and installation while underscoring its commitment to energy efficiency and high-performing buildings. Graboyes starts work on its largest project to date — Alden Park, a historic apartment complex built in and added to the National Register of Historic Places in The three sets of towers have more windows than the Empire State Building.
Graboyes is again listed as one of Inc. Graboyes Commercial Window Company announces that Ellis Guiles is its new president when Guiles and investment partners acquire the company. With the new ownership, Graboyes Commercial registers as a Minority Business Enterprise MBE and begins expanding its offerings and building its smart envelope and building performance position within the sustainable building market of the Mid-Atlantic region.
Guiles is named to the advisory committee of the Philadelphia District. Among a significant roster of completed projects during , Graboyes Commercial Window Company completes the second phase of its largest project to date with historic window replacements totaling 6, windows during phase one and additional windows during phase two at the c. Graboyes installation crews achieve completion in 14 months, four months ahead of schedule.
antique Art Nouveau American stained glass window, dating from the ‘s. architectural or historical significance, or one-of-a-kind location or character.
Crown glass was an early type of window glass. In this process, glass was blown into a “crown” or hollow globe. This was then transferred from the blowpipe to a punty and then flattened by reheating and spinning out the bowl-shaped piece of glass bullion into a flat disk by centrifugal force , up to 5 or 6 feet 1. The glass was then cut to the size required. The thinnest glass was in a band at the edge of the disk, with the glass becoming thicker and more opaque toward the center.
Known as a bullseye , the thicker center area around the pontil mark was used for less expensive windows. In order to fill large window spaces with the best glass, many small diamond shapes would be cut from the edge of the disk and these would be mounted in a lead lattice work and fitted into the window frame. Crown glass was one of the two most common processes for making window glass until the 19th century.
New research led by the University of Reading has revealed that finds at Glastonbury Abbey provide the earliest archaeological evidence for glass-making in Britain. Glass furnaces recorded in —57 were previously thought to date from before the Norman Conquest, but radiocarbon dating has now revealed that they date to much earlier, roughly to the s, and are likely to be associated with a major rebuilding of the abbey undertaken by King Ine of Wessex.
We have documentary records of glass-making at York and Wearmouth for the s, but Glastonbury provides the earliest and most substantial archaeological evidence for glass-making in Anglo-Saxon Britain.
This post is based on his research on historic window glass, where the primary aim is to improve the conservation of historic glass by providing a.
The window is so large that the stained glass was re-installed in two stages. In , of the panels were replaced. Then, between August and September , restorationists worked on the remaining panels, returning them to the church between November and January Half of the window depicts the creation of the world from the Book of Genesis. The other half is a tells the story of the Book of Revelations and the events that presage the return of Christ and the end of the world.
It is also home to the five sister windows , which date to the mids. After World War I, that window was restored and was rededicated as a monument to the women of the British Empire who died while serving their country during the war, including Edith Cavell , a nurse who was executed in after helping more than Allied soldiers escape from German-occupied Belgium. It was restored in because of erosion. These and the rest of the medieval windows throughout the cathedral will also received the UV protective glazing over the next 20 years.
The study of archaeologically-retrieved window glass is in many ways distinct from the study of window glass still in-situ in buildings, as it requires not only recognition of fragmented motifs, date and style, and iconography where possible, but also consideration of the excavated spatial patterning, physical processes of destruction, selection, and deposition, within varying archaeological contexts. Dr Emma Wells was a regular contributor to Vidimus , the only on-line magazine devoted to medieval stained glass, whilst completing her PhD at Durham.
Some major published projects have been completed at Durham, including the high and late medieval glass from Glastonbury Abbey in Gilchrist, R and Allum, C forthcoming, Glastonbury Abbey Excavations , London, Society of Antiquaries of London, due out View the latest news on the project. Learn more about our project with the Palace Museum.
The measurement of the thickness of window glass to determine relative dates for historic-structure sites has been practiced by historical archaeologists for
We have a couple of window panes that have names, dates, and even a branch with leaves etched in them — all from the 19th century. Is it true that ladies would test their diamonds or other gems to see if they were real or glass by doing such etchings? If only it were that easy! Many high quality imitation diamonds made in recent decades are harder than glass, so even fakes will scratch glass.
Take it to a reputable, local jewelry, one who has been in business for many years, and he or she will tell you at no cost whether it is genuine or not. They will not appraise it at no cost—for that you need an experienced CGA or Certified Gemologist Appraiser who has the training to judge your jewelry value it.
To browse Academia. Skip to main content. Log In Sign Up. Download Free PDF. The Value of Historic Window Glass David Dungworth.
Assigning an accurate date, maker, and style to a stained glass window often.
David Dungworth works for the Heritage Protection Department and is part of the team that provides English Heritage with specialist skills in heritage science. This post is based on his research on historic window glass, where the primary aim is to improve the conservation of historic glass by providing a means to identify which panes are original and which are later replacements.
I work in a laboratory where we use techniques from materials science to study artefacts and materials, from creation, through use, modification, burial and recovery and subsequent investigative analysis. One of our recent projects has been looking at historic window glass. In the first phase of the project we collected hundreds of samples of historic window glass from both archaeological and architectural contexts. These were carefully chosen to provide us with some dating evidence for each sample.
In the laboratory we analysed each fragment of glass to determine its chemical composition. We found that the chemical composition of the glass reflects the raw materials used to make it and that the raw materials that were available have changed over time. All window glass has been made using sand but with the addition of a flux which will lower the melting temperature.
The earliest medieval glass was made using a flux obtained from the ash of woodland plants especially bracken. Late in the 16th century, French glassmakers came to England and their glass has a higher calcium content which probably reflects the use of a flux made from tree ash. From the end of the 17th century window glassmakers began to use seaweed ash as their flux and we see this in the strontium content of the glass.
In the s the window glass was revolutionised by the introduction of a pure sodium carbonate flux which was made on an industrial scale. Further changes in the chemical composition of window glass are mostly related to the increased mechanisation of the window glass industry.