Mold Seam Most bottles produced in the past years were formed by blowing molten glass into a mold. The statement was not required on wine or beer bottles, the latter category which was - and to some degree still is - bottled in re-useable bottles. Do not estimate a bottle's age by its shape.
Without the stippling the thermal shock that would occur with full base contact on the conveyor would create stresses that can cause the bottle to burst, or reduce its overall tensile strength. Author reserves the right to update this information as appropriate. Bottle made of some other color of glass If the bottle has some other glass color no useful general dating information is possible.
Click knurled base to see such as defined by a Owens-Illinois engineer Phil Perry, pers. This is done to allow the user to get more information or clarification as they proceed through the key. In addition, other references beyond the scope of this website usually must be consulted to get as complete of a dating and typing story as is possible for any given bottle.
Post Bottles Do the mold seams go all the way from the base to the lip? This was almost universal with many beverage bottle types e. Thus far, I have found no datable, mouth-blown, El Paso soda bottles containing volume information. When present, bottle makers marks can be an excellent tool for helping with the dating of historic bottles.
How much would this bottle be worth. The curious student of glass items will quickly learn when a lip has been formed onto the bottle and when it was applied by hand. This is especially true of later machine made bottles, i. This is the base of the bottle whose lip is shown above left.
Consider the answers and dating overlap information provided by the above questions together in arriving at a likely age range for your bottle. These numbers help to determine general dating break probabilities for both machine-made and mouth-blown bottles. There were some wide mouth, semi-automatic machine produced bottles albeit a very low percentage which had machine-made characteristics minus a suction scar than can date back as early as the mids. The earlier green glass ink bottle is also certainly machine-made, most likely on an early semi-automatic, interracial dating christian blow-and-blow machine based on its crudeness and lack of a suction scar. Other types of base perimeter stippling resembles small crescents - - which is very common on modern beer bottles.
In any event, the suction scar is never found on mouth-blown bottles though suction scars are sometimes referred to as a pontil scar by the unfamiliar. Also keep in mind that bottles could have been used and refilled multiple times. Occasionally, you will see base embossing of patent dates or the classic Rickets Patent of midth century era. Also, the format and space constraints of a journal article do not allow for the elaboration and illustrations necessary to make a key function fully Jones b. That would be only for the exceptional piece.
- Many specialty bottles were imported from Europe, though that fact may be at times hard to impossible to ascertain.
- The numbers on the base do suggest that this is a later machine-made bottle, but I would really like to see a photo.
- If your bottle has this statement embossed in the glass, it is a machine-made liquor bottle that dates between and the mids.
- Specific embossing found on bottles can be an immediate indication of age.
- The disk-like mark is sometimes confused with a pontil.
The food and household product industries on the other hand widely adopted the screw cap quickly. This requirement was intended to discourage the re-use of bottles by bootleggers and moonshiners, though the biggest discouragement to that illicit activity was that liquor was now legally available. Another exception example is that the bottles for expensive, low production liquors e.
Guidelines for Determining the Age of Antique Bottles
DATING BOTTLES BY THEIR TOPS AND BASES
Estimating the age of antique bottles can sometimes be a difficult task even for the experienced collector. Bold and garish colors are also rare in antique bottles, so beware of bright reds, greens, yellows and purples. How to Identify Genuine Antique Decanters.
However, this feature is still a tenuous one since there are many early machine-made bottles with few or no bubbles. This closure can be found on Whisky and medicine bottles of the period. See the About This Site page for more information about the author and contributors.
The side mold seam does not extend onto the top surface of the finish, i. The pictures below are from two early machine made medicine bottles. There are huge numbers of bubbles and impurities in the glass. Any idea where I can research more on it.
Film clip is compliments of the Owens-Illinois Glass Company. They had their own printing department and produced a huge variety of trade cards, almanacs, calendars, libra man dating etc. These bottles are discussed in more detail in the ink bottle section of the Household Bottles non-food related typology page.
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. If it were that simple much of this website would be unnecessary! None of the stippling - given the indented nature of the base center and lack of stippling on the resting surface - would have come in contact with the conveyor belt. The the lower left corner you can see evidence of the diagonal mold seam which at one time bisected the base. This was the manner in which the early Owens bottles were blown.
The second individual had never seen one. The earliest bottles were hand-blown by a glassblower with a blowpipe and lack seams. The above and linked photos courtesy of Carol Serr. Most bottles produced in the past years were formed by blowing molten glass into a mold.
The types of bottles illustrated on these pages would be considered typical of the earliest machine-made bottles in the U. Acceptance often occurred over a period of many years or decades in some cases. In the s, the bottle mimicked early forms which were hand tooled and sealed with a cork. Thus, these questions do not have to be viewed in order. This will be shallower, wider and more perfectly circular than a pontil mark.
Machine Made Dating
Having written extensively on North American archaeology and material culture, he has contributed to various archaeological journals and publications. Both of the pictured bottle bases note such with the script Duraglas on the base. Move to the other questions below for more dating opportunities. The circle is incised or sharply indented into the surface of the glass and can be distinctly felt by running ones fingernail over the mark.
- In one glass factory a wall had to be erected between the hand operations and the newly installed machine to prevent sabotage.
- The image to the right is a close-up of a small, medium green, machine-made ink bottle.
- For the first decade or so of use i.
- Machine-made s oda bottles were generally not decolorized with manganese after Lockhart a.
- The picture to the left shows both of these mold seams click to enlarge.
- Apparently to denote measurements.
Dating Your Old Bottles
The three questions found on this page below answer several basic questions about a given bottle. There are a few bottles made for them that are quite scarce today namely the Ocean Weed Heart Remedy which bring hundreds of dollars. Click on the machine-made beer bottle picture above to see an illustration of this bottle showing the major diagnostic characteristics of a typical machine produced bottle. This mark is distinctive to the suction process which feeds glass into the bottom of an Owens machine's parison mold.
Dating Antique Bottles
RE Bottle Dating
See the milk bottle section of the typology pages for more information. However, a large majority of bottles in the U. The concentric rings are not always as obvious as the picture shows click to enlarge and sometimes not visible, though if present it is a conclusive diagnostic feature. The pontil is a definitive mark that dates glass.
The seams seem to run only partially up the neck of the bottle with a smooth lip. Bottle made by the Owens-Illinois Co. Thus, the presence of a valve mark on a soda or beer bottles would indicate a narrow manufacture date in the early s.
Thousands of people ask Digger questions about their bottles. Can I open it up and clean it? Keep in mind that older technology often persisted and some bottles date later than you might think. This allowed an assistant to hold the bottle while a glassblower would attach and finish the lip of the vessel. For a broader discussion of this subject see Lockhart, et al.