Today in 1949, US Patent 2468840 A was issued, an invention of Robert C. Schock, for his “Heater For Wort Kettles.” There’s no Abstract, but in the description it states that the “invention relates to means and methods of heating wort prior to its use in the making of beer.” A little later on, they add that the “invention comprises a heating unit having varying heat units supplied to it for their exchange with a mass to be heated, and to keep said mass heated, such exchange taking place at relatively lower temperatures, then at relatively higher temperatures, and then again at lower temperatures, the latter if desired.”