Archaeological Artifact: Window Lead 

Dec. 17, 2018

Figure 1. Leaded Casement Window, 17th century, Museum of Fine Arts, Boston. Accession No. 27.794.

By: Jeanne A. Ward, RPA and Alexandra Glass

Early in the colonial period window glass was a bit of a luxury becoming more common place with time.  It shows up on almost all main house sites after about 1640 and the fragmented remains are not uncommon on early historic archaeological sites.   As expected fragments of early window glass have been recovered from excavations at Cloverfields.

In addition to the fragments of window glass, another window component which has been identified at Cloverfields are fragments of the thin lead strips which once held the delicate panels of glass together.  Casement windows are a style of window which open inwards or outwards on hinges.  They could also be fixed panels from the building similar to the way a door might. Small panels of thin glass were often held together using strips of lead (cames) and then surrounded by an iron or wood frame (Fig.2).  Thin strips of lead were passed through a vice-like machine to form an “H”-shaped came. Glass panels could then be inserted and secured in place. As the lead passed through the vice, the glaziers initials and a date were often imprinted at intervals on the interior of the strip. Casement windows decreased in popularity during the 18th century, replaced by sash windows; a window type where the glass was more commonly framed solely by wood rather than lead, incorporated larger sheets of glass, and slid up and down within the frame.

Figure 2. Selected window came fragments from Cloverfields house excavations. Top row: Top view, Bottom Row: Side view of middle section with mill marks.

For archaeologists and architectural historians, the quantity and presence of window cames can provide several points of information including: approximate building dates, window type, and where windows may have been located. Since window leads can include the glaziers initials and date of milling, it is possible to gently open crushed archaeological specimens and view any information printed on the interior of the lead. While not necessarily providing a 100% accurate date for the building or site or its context, the date on the lead, when combined with other artifactual evidence, can help with developing site chronologies.  Also, since window technology changes during the 18th century, the presence or absence of window leads on a site can create a case for one window type over another.  Analyzing the quantity of window leads and identifying exactly where they cluster on a site can indicate to researchers where casement windows may have once hung, or whether it is more likely the windows were sash windows.

At Cloverfields, a total of nine window lead fragments have so far been identified from various areas surrounding the house (Fig.2).  Unfortunately, none have yielded dates or glaziers initials.  Interestingly though, a broken window lead vice is listed on the 1738 Hemsley inventory.

It appears that the earliest iteration of Cloverfields included casement windows which were replaced during one of the early renovations.  Two types of casement window frames have been discovered reused in the Cloverfields house and seem to indicate that one set dates from initial construction and a second perhaps from the 1728-29 remodeling.