APPENDIX III MARKS LEFT BY DIFFERENT TECHNIQUES OF BOTTLE MANUFACTURE

Free-blown bottles usually date before the second half of the nineteenth century and are characterized by an absence of mold lines of any sort. Because no molds were used, these bottles are often asymmetrical. Dip-molded bottles, or bottles molded for basic body shape below the shoulder, are also generally pre-Civil War and can only tentatively be distinguished from free-blown bottles by their symmetry below the shoulder and a slight tapering from shoulder to base. Bottles blown in a two-piece mold have mold lines extending up two opposite sides, usually to just below the tooled lip. On early nineteenth century bottles of this sort, the mold lines continue across the center of the base, but after the 1850s, most two-piece molds had a separate base part, either a cup bottom, in which the seam encircled the outer edge of the base, or a post bottom, which left a circular seam on the bottom of the bottle. Most bottles from the Middleton Place privy were blown in two-piece molds with cup bottoms.

The three-piece mold leaves a single horizontal line around the shoulder of the bottle, and vertical lines extending up either side of the shoulder. The height of these lines can vary from partway up the shoulder to nearly to the top of the neck. A turn-molded bottle has been rotated in the mold to erase mold marks and will exhibit faint horizontal scratches and striations on the body and neck.

Embossing, very popular after the Civil War, usually consists of the name of a company or product printed in raised letters on the sides or base of the bottle. Isolated numbers and letters on or just above the base are usually, but not always, mold numbers used by the manufacturer for identification. Embossed letters are sometimes carved into the body of the 63 mold, but for smaller runs a plate mold, with a removable lettered plate on one or more sides, was used.

Mold lines on bottles finished with a specialized lipping tool are usually obliterated by faint horizontal striations extending to about a quarter inch below the lip. The two-piece blow-back mold, however, leaves mold seams to the very edge of the lip, and a lip surface that has been ground smooth rather than shaped with a lipping tool.

A pontil mark is a circular scar left on the base by the iron rod used to hold the bottle for finishing the neck and lip. Although there are many different methods of empontilling, only two types of marks were found on bottles from the Middleton Place privy. One is a “sand pontil mark,” a roughened grainy area covering most of the base, apparently the result of dipping the glasscoated pontil iron in sand before attaching it. The other is a “blow-pipe pontil mark,” which results from empontilling a bottle with the same pipe that was used to blow it. A blow-pipe mark is a distinct ring of glass the same size as the bottle neck.

Pressed glass is formed with a plunger in a mold on one or more pieces. Pressed glass items are comparatively thick-walled, have smooth molded lips, usually with mold seams, and often are distinguished by a short, straight shear mark, like an isolated mold line, on the inside base. This mark is from the severing of the “gob” of glass before it is dropped into the mold. Bottles that are made on either automatic or semi-automatic machines will have mold lines encircling the top of the lip, as well as on the sides and base.

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