just in case

I ever get a reference question about the history of the Mason jar, I now know where to go:

Barclay, John C. The Canadian fruit jar report : an illustrated book of all known Canadian fruit jars and produce jars, plus a brief history of the glass works in Canada. Kent Bridge, Ont: J.C. Barclay.

(FYI, this book popped up in the results list for a title search on "History of the Book in Canada." If you ever want it, it's at the ROM Library, where all the fruit-jar enthusiasts hang out.)