Complex sentence: Mary's name survives in her invention of the "bain-marie", which limits the maximum temperature of a container and its contents to the boiling point of a separate liquid: essentially a double boiler.
Split into simpler sentences: Mary's name survives in her invention of the bain-marie. A bain-marie limits the maximum temperature of a container and its contents to the boiling point of a separate liquid: effectively a double boiler.