Machine made glass in the archaeological record

Glass, it's been in every historic site I have ever worked on. Even digs in what look like empty fields usually contain glass and it's usually broken bottles of one kind or another. Sometimes it serves as a nice indicator of the era you are dealing with and whether or not you have cleared disturbed soil or are simply in historic strata. In short, it's useful. Especially if you learn to tell machine made bottles from mouth blown, not dead simple but an off the cuff indicator that you are working with something post 1903 is the presence of machine made bottles. Pretty cool. 1903 was the year a guy by the name of Michael Owens unveiled what the Corning glass company calls the most significant advance in glass production on over 2000 years.

The knowledge of how to go about dating bottles can be gained in a number of ways, field and lab work, hours of nosing through antique stores and eBay or, thankfully, via a handy site run by a Department of the Interior, Bureau of Land Management employee! Whew that's a lot of bureau but it's a great resource laid out so you can look at an artifact and run through a series of questions to help pin point the date of a given bottle within ten years or so of it's date of manufacture. Absolutely worth checking out if you have even minor interest in the topic.

http://www.sha.org/bottle/machinemadedating.htm