BLACK CHERRY JAM
From the 1946 Good Housekeeping cook Book

3 lbs (3 1/2 cups) fully ripe Bing or other sweet cherries
7 cups (3 lb) sugar
1/4 cup fresh, frozen, or canned lemon juice
1 (8 oz) bottle liquid fruit pectin

Sterilize about 11 jelly glasses, lids, and rings.

Remove stems and pit cherries, chop cherries fine.

Into large saucepan, meaasure 3 3/4 cups fruit. Add sugar and lemon juice; mix well. Bring to a full rolling boil over high heat; boil hard 1 minutes, stirring constantly.

Remove from heat. Stir in pectin at once. With metal spoon, skim off foam; stir and skim by turns 5 minutes.

Fill prepared jelly glasses at once. When glasses are cool, cover with lids and rings. Process 10 minutes in a boiling water bath.