This bottle dating "key" is a relatively simple "first cut" on the dating of a bottle.While running a bottle through the key questions, the user is frequently directed to move to other website pages to explain diagnostic features and concepts as well as to add depth and/or precision to the initial dating estimate.In short, there was (and is) nothing to stop a glassmaker from using an obsolete method in the production of a bottle.3.Some technological changes were expensive and not adopted by glass makers until it became an "adapt or perish" issue and many glass factories just perished.An example of this is the finding of a few pontil scarred utilitarian bottles among otherwise late 19th or early 20th century refuse.It is unlikely that this bottle was made during the same era, but instead was reused for a lengthy period or otherwise retained until broken or discarded.
This was almost universal with many beverage bottle types (e.g., soda, beer, milk) but was variably common with just about any type bottle - especially prior to 1920.All this adds to the fascination with bottle making, but makes systematic dating similar to solving Rubik's cube - ostensibly simple on the surface but complex in practice.To misquote an old saying as rephrased by the BLM supervisor that facilitated the initiation of this website project: "The universe (of bottles) isn't just more complicated than you think, it's more complicated than you CAN think." True to a large degree, though much information can be teased out of most bottles with a systematic approach to the matter. This Bottle Dating page (and website in general) is designed to address what the website author refers to as "utilitarian" bottles & jars (click for more information).Utilitarian items include canning/fruit jars and figured flasks since they were intended to be reused by the purchaser and have been observed to follow well the dating guidelines, though there are some manufacturing timeframe differences with canning jars.(Click canning jar to view the typology page section devoted to that category.) The beer bottle pictured to the above left is a classic example of a utilitarian bottle from the late 19th century that was typically reused.Acceptance often occurred over a period of many years or decades in some cases.