A hundred years ago most people had wood or coal stoves – and ovens didn’t have thermostats. Here’s advice in an old home economics textbook about how to determine whether the oven was at the correct temperature for successfully baking cakes:
Baking Sponge Cakes [Cakes without Fat]: A practical test for the temperature of the oven is the placing of a bit of flour or white paper in the oven. If at the end of 5 minutes the paper or flour is slightly browned, the oven is of proper temperature for sponge cakes or cakes without fat.
Baking Layer and Loaf Cakes: If a bit of flour or white paper is delicately browned after being placed for 2 minutes in the oven, the oven is of proper temperature for layer cakes containing fat. For a loaf cake the oven should be cooler, since a longer time for baking is required. It is especially important that a crust does not form over the top of a cake before the cake has risen, or before it has been in the oven one-fourth of the time required.
A Textbook of Cooking (1915) by Carlotta Greer