Of course, every cook would have a different definition of the various temperatures used in cooking. There were no standard temperatures in cookbooks and anyone transmitting a recipe to someone else they cannot transmit the experience needed to make it successful.
Before temperature gauges or even ovens, the cookies were baked last in the day, the oven, slowing or cooling at the end of the baking day. Knowing an oven's temperature could just come from experience but often, one would thrust an arm into the oven and count the seconds before it became too difficult to keep it there. The number of seconds would give an idea of the temperature.
Here is a table which gives a range for the temperatures in old recipes.
Common Temperatures and Conversions
Temperature Notes Fahrenheit Celsius
Very cool oven 225°-250° 107°-121°
Cool oven 275°-300° 135°-149°
Very moderate oven 325° 163°
Moderate oven 350°-375° 177°-191°
Moderately hot oven 400° 205°
Hot oven 425°-450° 218°-233°
Very hot oven 475° 246°