Dating your mason jar
Contrary to most other food bottle categories, canning jars have indeed received significant attention from researchers.The incredible variation in jar brands, and in particular, the hundreds of different closure types, has piqued the interest of collectors and researchers for decades and inspired many authors to approach this category with zeal and research depth (Toulouse 1969; Creswick & Rodrigues 1969; Roller 1983; Creswick 1987; others).In Munsey's (1970) classic book "The Illustrated Guide to Collecting Bottles" he used separate chapters for "Fruit Jars", "Food Bottles", "Milk Bottles", and "Candy Bottles" - all of which are covered within this "Food Bottles & Canning Jars" typing page.Conversely, Munsey also lumped into the "Food Bottles" chapter types which are separated here into subject categories, i.e., "Sauces & Condiments", "Pickles & Preserved Foods", and "Vegetable Oil & Salad Dressing Bottles" - all of which also have sub-categories under those main headings.Nicolas Appert who is generally recognized as the father of the canned food industry.His work was prompted by the offering of a reward in 1795 by the French government (12,000 francs) for a viable food preservation process.Along with figured flasks (Mc Kearin & Wilson 1978) and possibly Western liquor bottles (Thomas 1974, 1977, 1998a & b, 2002), canning jars have had some of the best historical research done on them though all of the "good" books are long out of print.
Appert's process involved the killing of the bacteria by heating followed by exclusion from further contamination in a sealed container, although the actual scientific reasons as to why the process worked were unknown at the time.
The incredible variety of fruit/canning jar closures were a prime example of closure importance - a subject discussed later on this page.
(A "Lightning" bail type canning jar closure is shown on the canning jar pictured below.) Due to the similarities, this typology section also contains the large category of fruit/canning jars as they were definitely designed and used for food preservation containers though envisioned and marketed as being indefinitely re-usable (until broken) whereas the other food containers discussed here were largely used once and discarded.
Part of the boundary between Pennsylvania and Maryland established by the English surveyors Charles Mason and Jeremiah Dixon in the 1760s.
The line resolved disputes caused by unclear description of the boundaries in the Maryland and Pennsylvania charters.