An patent granted to Joseph B

Dating sun drop bottles

This bottle also

Post bottom mold produced bottle. An illustration of the sabot can be found in the book Antique Glass Bottles - Their History and Evolution by Willy Van de Bossche which is still widely available. The pictured base also has the initials A.

Key mold base with the deceptive appearance of a post base mold. If so, they would have been essentially a dip mold with two shoulder mold sections added.

The bottle pictured to the left also had a separate base plate even though the bottle is largely unembossed there are mold numbers very faintly embossed on the base. Mouth-blown bottles portion of the Dating Key.

Other manufacturing based diagnostic features

The sabot likely made its way to the U. The snap case tool had a center post which cupped the base of the bottle and at least two bars or flanges that grasped the sides of the bottle. This is shown distinctly in the picture at the following link - dip mold bottle shoulder. Sometimes a bottle will appear to have the surface texture of the body sides indented or roughed up by the tool or the sides slightly flattened by over-compression.

Other manufacturing based diagnostic features must be used. This bottle also has a glass tipped pontil scar. Though not always totally accurate it is a reference that is unlikely to go away because of its pervasive use. Valve or ejection marks - Discussion of a small round scar on certain types of machine-made bottle bases. Typically the heel and extreme lower body of a free-blown bottle flares out slightly with the base diameter being slightly wider than the average diameter of the bottle body.

Most of the above points also apply to the base of a free-blown bottle which will not be symmetrical i. Hinge mold bases can date back to at least in the U. Square or rectangular posts are very unusual but do exist as evidenced by the base of the s era gothic pickle bottle at this link- gothic pickle. The post mold seam circle or oval is frequently hard or impossible to see or feel as it is often integrated into or masked by molded base features like a depression or shallow push-up. The side mold seams progress around the edge of the bottle heel and end at the outside edge of the round concave indentation which contains the pontil scar and which was formed by the post plate.

Three-piece mold bases One of the earliest mold types to be used in the U. There are no mold seams, no embossing, no moulded decorations, and the exterior glass surface tends to be smooth and glossy, patinated areas excepted. Otherwise the mold would not open properly once a bottle was blown in it. As shown in the picture to the left Dr. However, this is often hard to ascertain and the best way to tell a dip molded bottle from a similar free-blown bottle is to look at the body and shoulder.

The mold seam for the center post is visible in the picture to the above right as the circle just inside the base embossing and just outside of the sand pontil scar. Different molds produced different base configurations. It is usually difficult or impossible to conclusively differentiate the subtle markings of a snap-case or sabot from the array of possible mouth-blown mold or glass making imperfections. However, similar to so many other aspects of historic bottle dating, there are exceptions or variations based on the type or style of bottle and even bottle size. All these variations served the same function of centering the mold halves better as the mold was swung shut.