Acceptance often occurred over a period of many years or decades in some cases.This technology lag makes some diagnostic characteristics better than others for dating. As a corollary to #1, consider the following quote: "Treat terminal dates with care.The information on this website will, however, usually produce a reliable manufacturing date range for a majority of American utilitarian bottles manufactured from the early 1800s to the mid-20th century.Using physical, manufacturing related diagnostic features, most utilitarian bottles can usually only be accurately placed within a date range of 10-15 years (i.e., 1870-1880 or 1885) . Like many industries making the leap from manual craftsman production to industrialization and automation, technological advances in bottle manufacturing were not immediately accepted by glass manufacturers or their workers.Produced during the era where all bottles were an relatively rare and cherished commodity to be discarded only when broken (i.e., the first third of the 19th century back many centuries prior) and does not otherwise fit the above two categories.
Unfortunately, the complexities of precisely dating bottles is beyond the scope of any simple key.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.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.We can always have some indication of a starting date for a technique if we can find who first put the idea into practice.But any technique, once developed, can be used right up to the present - as many collectors know who have been so unfortunate as to rely too heavily on a popular termination date as sure evidence of true antiquity..." (Toulouse 1969b).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.Other diagnostic tools must be used to date these items.Shape is more indicative of function - i.e., what the bottle was used for or contained - but even that has a myriad of exceptions.