Smith College Fudge

This recipe is from Chocolate and Cocoa Recipes, a little chocolate cookbook printed in 1909.

Melt one-quarter cup of butter. Mix together in a separate dish one cup of white sugar, one cup of brown sugar, one-quarter cup of molasses and one-half cup of cream. Add this to the butter, and after it has been brought to a boil continue boiling for two and one-half minutes, stirring rapidly. Then add two squares of Baker's Premium No. 1 Chocolate, scraped fine. Boil this five minutes, stirring it first rapidly, and then more slowly towards the end. After it has been taken from the fire, add one and one-half teaspoonfuls of vanilla. Then stir constantly until the mass thickens. Pour into buttered pan and set in a cool place.