First this cautionary note: Bottle dating just isn’t a exact technology! Utilizing simply physical, manufacturing associated features that are diagnostic many utilitarian containers can frequently simply be accurately placed within a romantic date number of 10-15 years (for example., 1870 to 1880 or 1885). You’ll find so many good reasons for this:
1. Like numerous companies making the leap from manual craftsman production to industrialization and automation, technical improvements in container manufacturing weren’t straight away accepted by cup manufacturers or their employees. Recognition usually happened over a length of several years or years in some instances. This technology lag makes some characteristics that are diagnostic than others for dating. This is noted where understood.
2. Being a corollary to #1, think about the after estimate: “Treat terminal times with care. We could also have some indicator of the date that is starting a strategy whenever we will get whom first place the concept into training. But any method, as soon as developed, can be utilized right as much as the current – as much enthusiasts understand who’ve been therefore regrettable as to count too greatly for a termination that is popular as certain proof real antiquity. ” (Toulouse 1969b). In a nutshell, there is (and it is) absolutely nothing to stop a glassmaker from utilizing an obsolete technique in the manufacturing of a container.
3. Some technical modifications had been high priced and never used by cup manufacturers until it became an “adapt or perish” problem and glass that is many just perished.
The change into the completely automatic container device from mouth-blown and some semi-automatic practices during the early twentieth century is the classic instance (Toulouse 1967, 1969a). (begin to see the Glassmaking & Glassmakers web page)
4. The exact same container could have now been recycled and reused several times for several years before finally being discarded – entire or broken (Busch 1987; see website website website link below). It was very nearly universal with numerous drink container kinds ( e.g., soft drink, alcohol, milk) but ended up being variably normal with virtually any kind container – specially just before 1920. Needless to say, soft drink & alcohol containers were reused up to quite recently; milk containers beyond the mid-20th century. The bottle pictured into the right has a Wait’s Liver and Kidney Bitters label pasted throughout the embossing of a celebrity Kidney and Liver Bitters bottle! (the 2 items were from split organizations that have been cross-town Sacramento, CA. Competitors through the belated nineteenth to century that is early 20th. The writer has additionally seen celebrity Bitters labels on Wait’s containers in 
addition to both labels from the period that is immensely Hostetter’s belly Bitters bottles! )
Reuse, needless to say, will not replace the production date of this container it self, but care should be exercised while using the known date of just one or a couple of containers up to now other products discovered through the context that is same. Each time a most likely or known “older” item is situated in a known “newer” web web site it really is described as deposition lag. A good example of this is actually the choosing of the few pontil scarred utilitarian containers among otherwise belated 19th or century refuse that is early 20th. It really is not likely that this container ended up being made through the exact same age, but alternatively ended up being reused for a long duration or otherwise retained until broken or discarded. Pontiled base fragments may possibly also be from later on produced “specialty” bottles that are described below.
5. Some container forms are indicative of a particular production age, though numerous container styles/shapes had been utilized for countless years
– such as the cylinder whiskey “fifth” or square snuff container – that the design it self is not indicative of age. Other tools that are diagnostic be employed to date these things. Shape is more indicative of function, in other words., just just what the container had been utilized for or included, though also that will have an array of exceptions. Start to see the Bottle shapes that are typing/Diagnostic to learn more about the niche.