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"gob feeders") though a similar type mark without the feathering is induced by the parison/blank mold of most other blow-and-blow machines - including up to the present day.

Press-and-blow machines usually have a round valve mark on the base but lack either the suction or parison scars.

The ghost seams are caused by the parison mold parts and if visible enough will be "attached" to the vertical seams in the finish.

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Feature #2 (mold seam diameter) is not as strongly diagnostic as the primary indicators as mouth-blown bottles sometimes can have very fine mold seams.

Feature #7 describes a couple glass related features that are quite consistent in machine-made bottles, but not diagnostic, i.e., mouth-blown bottles may sometimes have few/no bubbles in the glass and even thickness.

Both seams are quite diagnostic of machine manufacture and are usually visible, though the seam at the top of the finish can be hard to see on some bottles - especially if the finish was fire polished.

In the glassmaking trade, these seams along with the side mold seams within the finish or just below are referred to as "neck ring" or "neckring" seams since they were formed by the separate neck ring portion of a machine mold (Tooley 1953).

General Machine-made Diagnostic Features: Machine-made bottles will exhibit most or all of the diagnostic characteristics explained and illustrated below.

(This summary is largely an amalgam of Toulouse 1969b; Miller & Sullivan 1981; Jones & Sullivan 1989; Boow 1991; Cable 1999; Miller & Mc Nichol 2002; Miller & Morin 2004; empirical observations.) It should be noted that features #1, #3, #4, #5, and #6 are primary indicators of machine-made manufacture.

This mark is distinctive to the suction process which feeds glass into the bottom of an Owens machine's parison mold.

(Note: A movie clip showing this process in action is linked at the bottom of this box.) Suction scars can not be produced by feed and flow automatic machines (i.e.

It was noted in 1910 that the Cumberland Glass Company (Bridgeton, NJ) had "...succeeded in perfecting a machine that will satisfactorily produce narrow neck bottles, such as catsups, beer bottles, etc., at a big saving over the hand method." The method used was unusual and may have been unique in bottle-making history: "The machine differs from all others, and in getting the neck upon the bottle, the vessel is made in two sections, the neck being put upon the bowl with a second operation. Manager says machines are fast coming into play in bottle industry, plans eventually to have machines in place of "carrying in boys." Location: Clarksburg, West Virginia" (Library of Congress).

This is accomplished so that there is no perceptible mark upon the bottle showing the joint, and the bottle stands every possible test as to strength. Although products of this machine are not conclusively known a bottle such as the one at this link - offset seams shoe polish bottle - may well be a product of the described machine as there is a distinct and abrupt interface edge at the shoulder where the mold seams for both the body and neck end and are offset. This two table semi-automatic machine would have been hand fed with glass (furnace likely to the right) and does have the two different mold sets with the parison molds (where the first "press" part of the cycle took place) the set on the right.

Though patented and first used to a limited degree in 1903, the first Owens Automatic Bottle Machine licenses were granted to other manufacturers in late 1904 making 1905 the effective "beginning" (i.e., terminus post quem) date for bottles with all of the above listed machine made diagnostic characteristics (Miller & Mc Nichol 2002).

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