Window glass is of two principal types. One has a pale-olive cast. A few fragments of this type have finished edges, indicating that they are from the perimeters of sheets of crown glass and that Mercer purchased whole crown sheets and had them cut up. It may be assumed that this greenish glass is the oldest, perhaps surviving from Mercer's early period. The other type is the more familiar aquamarine window glass still to be found in 18th-century houses. A large corner of a rectangular pane has the slightly bent contour of crown glass, which is the English type of window glass made by blowing great bubbles of glass which were spun to form huge discs. The discs sometimes were cut up into panes of stock sizes and then shipped to America, or else were sent in whole sheets, to be cut up by storekeepers here or to be sold directly to planters and other users of window glass in quantity. The centers of these sheets increased in thickness and bore large scars where the massive pontil rods which had held the sheets during their manipulation were broken off. The center portions also were cut into panes, which were used in transom lights and windows where light was needed but a view was not. Hence they served not only to utilize an otherwise useless part of the crown-glass sheets, but also to impart a decorative quality to the window. They are still known to us as "bullseyes." A piece of a bullseye pane of aquamarine glass occurs in the Marlborough finds. The pontil scar itself is missing, but the thick curving section leaves little doubt as to its original appearance. A similar fragment was found at Rosewell. XVII _Objects of Personal Use_ Costume accessories recovered at Marlborough are extremely few. There are six metal buttons, all of them apparently 18th century. One of flat brass (USNM 59.2004) has traces of gilt adhering to the surface; another of similar form (USNM 60.85) is silver; a third (USNM 59.2004) is copper. The silver button, 7/8 inch in diameter, could be one of two dozen vest buttons bought by Mercer for 18 pence each in 1741. A brass button with silver surface was roll-plated in the Sheffield manner (USNM 59.2004), thus placing its date at some time after 1762. "White metal"--a white brass--was commonly used for buttons in the 18th century, and is seen here in a fragmentary specimen (USNM 59.2004). One hollow button of sheet brass shows the remains of gilding (USNM 60.73). Only one example was found--a dark-gray shell button--that was used on under-garments (USNM 59.1819). Among the personal articles are two brass buckles, one a simple half buckle (USNM 70.72, fig. 83d, ill. 48), the other a knee buckle (USNM 60.139, fig. 83e, ill. 49). Except possibly for a pair of scissors to be mentioned later, a brass thimble is the only artifactual evidence of sewing (USNM 60.74, fig. 83b, ill. 50). Four thimbles, mentioned in Ledger B, were purchased in 1729, and four in 1731.)