Canning Vegetables

The secret of success lies in boiling only

From 1913:

First of all, have your kitchen clean and dusted with a damp cloth. If you are putting up string beans, break them into small pieces, wash them thoroughly, and scald your jars. Fill these up with the beans and half a teaspoon of salt to each pint jar, then fill to overflowing with cold water. Have a wooden rack to stand in the bottom of the wash boiler, place jars on the rack, the rubbers adjusted and the covers put on loosely, and pour cold water into the boiler about half way to the top of the jars. Now cover your boiler tightly and let the water in it boil for one hour after the boiling point is reached; then uncover the boiler to let the steam escape, seal jars tightly, and let them stand until the next day, then loosen tops, place in the boiler, and boil again as you did the first time.
Do this on three successive days, put the jars in the fruit closet when they are cool, and they will never spoil. The secret of success lies in boiling only one hour on each of the three days instead of one long boiling.