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.Beginning collectors often wonder how to tell the age of a particular bottle.
This motion also erased the mold seam in the process.
One approach to helping beginner identify their old bottles involves show them the bases of old bottles.
The picture below at the left shows an iron pontil on the base jof a historical flask circa 1865.
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.
Beginning collectors often confuse an Owen's ring with a pontil mark and it is easy to see why this happens.