Canning in the past

I was looking through the copy of Ball Corp's Blue Book, edition 29, which is apparently from 1972 or 1974. It's fascinating to see how things change. Then, they're introducing the now-standard lids with the red rubber circle that seals, and I doubt if anyone uses paraffin to keep air out of food. There's a food science section, with all the line drawings showing men in lab coats. There's a chart showing how many plants to raise of a variety of vegetables to can and feed a "typical family of 6 persons," though interestingly, the food planning guide on the next page has amounts for one person or a family of 4 (at 7 1-cup servings/week of citrus and tomatoes, put up 63 quarts for one person, or 252 quarts for a family of 4). I wish I'd realized I had a chart showing about how many pounds of raw produce needed to fill a quart jar. There's the usual details of recipes and detailed canning instructions for both hot water bath and pressure canning, as well as some suggestions for freezing. And there's all the dated, slightly muddy colored photos. Still, all of this is reasonable, if a bit dated, until the inside back cover: an image of a hand-towel with a recipe printed on it: How to Preserve a Husband. Oy.