Leaded Glass Windowpane
by Rebecca Remmey
Description: Triangular-shaped glass with lead caning. Caning at the longest part of the triangle extends 5” beyond solder joint of caning to the edge of the glass. Several imperfections in the lead (small gaps between front and back pieces, dents). Glass tint is clear.
Before the discovery of this fragment of leaded glass and other types of window hardware in the archaeological excavation lead by Dr. Cadzow, the only information we had regarding the windows of the original Manor House came from William Penn’s letters. Any relevant information to be found in Penn’s letters was scattered and ambiguous, but the excavation of this window fragment unearthed a wealth of new and verifiable knowledge.
The physical measurements of the artifact were in accordance with the measurements mentioned in Penn’s letters, thereby elevating the known window dimensions from mere probable conjecture to a solidly proven fact, finally backed up by physical and documentary evidence. Similarly, the general size and shape of this piece of glass served to give us the size and shape of the panes of glass in the upper sash of the second floor windows of the Manor House. This small, individual triangular window-pane would have been surrounded by many more of the same leaded panes, combining into a diamond patterned lattice window, a fixed type of window sash above the hinged casement windows.
From its materials, lead and glass, we could easily determine its origins, as it wasn’t until after 1739, when construction had already been completed for quite some time at Pennsbury, that any significant glass production took place in the Colonies. Therefore, we can be certain that this glass would have to have been imported from England and that the resulting increase in price also resulted in the increase of its value. Not only was glass expensive, the added cost of importing from England was increased by heavy taxation.
It was manufactured by hand in the long and difficult process of glass blowing, so that since glass was already rather expensive in England where it was made, it became extremely valuable in the colonies. The process began with sand, soda ash, and lime which would be cooked into a molten state and put onto one end of a five foot long metal tube, known as a blowing rod, which the glassmaker would then put his lips on the other end, blowing it into a bubble which was then taken to an open furnace, or “glory hole”, to soften, then spun out and flattened into a disc and left to harden, be annealed, and finally divided into multiple glass windowpanes.
For further reading, check out these sources:
Cadzow, Donald. “Excavations at Pennsbury.” Report to The Historic Commission, 1934.
Phillips, Steven J. Old-House Dictionary: An Illustrated Guide to American Domestic Architecture (1600-1940). Lakewood: American Source Books, 1989.
Tidlow, Evelyn M., Frederick L. Walters, Patrick W. O’Bannon, and Kenneth Jacobs. Historic Structures Report for Pennsbury Manor Morrisville, Pennsylvania. Eds. John P. McCarthy and Daniel G. Roberts. West Chester: John Milner Associates, Inc., 1987.
Tunis, Edwin. Colonial Living. New York: Thomas Y. Crowell Company, 1957.
Weener, Carol G. “Pennsbury Manor: A Study in Colonial Revival Preservation, Historic Preservation.” Thesis, University of Pennsylvania, 1986.