I personally love learning new things about antiques and collectibles. I also enjoy being able to share this knowledge with you. This is one good reason to sign-up for our informative monthly newsletter, throughout the month I search many sources for new information to pass on to my customer's. Below is some information that I recently found on the history of canning jars and zinc lids. I hope that you enjoy it. The familiar term Mason Jar came after its inventor, Mr. John L. Mason, who, at age
26, was a tinsmith in New York City. He perfected a machine that could cut threads into lids, which ushered in the ability of manufacturing a jar with a reusable, screw-on, lid. These jars freed farm families from having to rely on pickle barrels, root cellars, and smoke houses to get through the winter. For urban families, Mason Jars allowed excess fruits and vegetables to be preserved for use later.
Historians believe the first jars were made at Crowleytown's Atlantic Glass Works, in Crowleytown, New Jersey. These are very rare. These jars carry the familiar embossing "Mason's Patent Nov. 30th 1858". This date refers to the original patent date, not the actual date of manufacture. Jars carrying this embossing, often with other monograms, numbers, letters, etc., were widely
produced until about 1920. Most were produced in the 1880s-1910s. The identities of many actual manufacturers are unknown. The numbers that you find on canning jars represented a specific glass blower and his team. This is how the glass blowers got paid, by the piece and the numbers indicated to the "boss" how many jars a particular blower and team had made that day. Some collector's call it a mold number. Zinc lids with porcelain linings were created by Lewis Boyd filed a patent in 1869 for
"an improved mode of preventing corrosion in metallic caps" i.e. the glass or "porcelain" lining. This innovation kept food from coming in contact with the zinc in the screw caps. Boyd was actually one of three men who gained control of the patent for screw caps and jars originally filed by John L. Mason in 1858. "Boyd's Porcelain Lined Caps" or zinc screw lids for mason jars were interchangeable with
the other mason jars made by hundreds of different manufacturers. In an effort to cut down on the unnecessary use of metal, glass lids temporarily replaced the tin and zinc lids which had been used up until 1941. There was a rubber gasket that fit up into the zinc lid to provide the seal that you need for successful canning. IT IS NOT A GOOD IDEA TO USE THESE LIDS TODAY. A good way to date your old canning jars is to look at the bottom and see if there is
a pontil mark, if there is your jar is probably pre-1855. Older canning jars also have a rough lip, they did not have all of the sophisticated grinding machines that came about in later years. Seams are another indicator of age, the oldest jars were blown and do not have any seams marks at all. Machine-made jars, dating after about 1915, have mold seams extending from the bottom up to and across the top of the
jar. If the base of your jar has a round ring in it and the lip is smooth, your jar was probably machine made sometime after the turn of the century but probably before the 1930s. If the jar has a large, rough and jagged ring on its base, it was probably made between 1900 and 1930. Machine-made jars after the 1930s, have a more modern look and frequently have small scars on the bottom indicating they were
made on more modern, sophisticated machines. If your jar has gripping ridges on its side that allow a firmer grip on the jar then it was made after 1930 when these ridges were crafted and added to jars. Value depends on embossing, color and size. Common mason jars are worth about $6 but some rarer versions can be worth $100 or more to collectors. Square jars tend to bring more than round jars and jars with the number 13 are rumored to be
sought after by some collectors. The decline of home canning began after the end of the war. Home canning declined as large, more profitable farms began to replace the small farm in America. Fewer small farms meant fewer farmers and fewer people to work the farms. The 1950s and 1960s saw the rise of the supermarket, the fast food restaurant, and the frozen TV dinner. As we move into the final years of the 20th century we find that
the art of home cooking itself, let alone the art of home canning, is quickly disappearing from the popular culture. There are some reproductions out there so do your research and educate yourself on your canning jars. | 
