"For hours at a time she plunked away at C-ration cans."

Type C Ration Cans were developed in 1938. They were used by land forces when a Type A ration (fully cooked meal made from field kitchen or mess hall) or Type D Ration (military grade chocolate) was insufficient.

C rations were divided into M (meat) and B (bread) products: the M products were meat and beans, meat and vegetable stew, meat and spaghetti, ham, egg and potato, meat and noodles, pork and rice, franks and beans, pork and beans, ham and lima beans, and chicken and vegetables; the B products were biscuits, compressed and premixed cereal, candy-coated peanuts or raisins, powdered coffee, sugar, powdered lemon or orange juice, cocoa powder, hard candies, jam, and caramels. A C ration box (for 8 men) contained three M products and three B products per man per day: 48 cans between 8 men.