One of the preeminent natural philosophers of the Enlightenment, Benjamin Thompson started out as a farm boy with a practical turn of mind. His inventions include the Rumford fireplace, insulated clothing, the thermos, convection ovens, double boilers, double-paned glass and an improved sloop. He was knighted by King George III and became a Count of the Holy Roman Emperor. Thompson's popularity with women eclipsed his achievements, though...