Dating hand blown bottles
Beginning collectors often wonder how to tell the age of a particular bottle.
One of the most important clues to the age of a bottle is the style of the lip.
Embossed bases became more common and other markings began to appear on bottle bases such as initials for the glass works producing the bottles.
For the period from 1870-1910 bottles had hand tooled lips and smooth bases.
When the mold seam stops before the top of the bottle then the bottle is said to have been hand finished..The letters ABM (automatic bottle machine) are used to refer to these bottles.In the photograph there is a smaller ring and then a larger one (not as clearly visible). Both rings are very symmetrical and did not leave a rough mark like the punty rod.Early machine made bottles carry a distinctive mark known as the Owens ring, named after the inventor of the automatic machine at the Owens Glass Company.The fruit jar shown below was made about 1920 and shows the Characteristic Owens ring.