William Robert Grove (1811-1896) was a giant of science in the nineteenth century, but he's largely been forgotten today. A pioneer in the harnessing of electrical energy, he invented an early battery known as the Grove Voltaic Cell, developed one of the first incandescent lights, and created the first fuel cell, using an approach that is still the basis of fuel cell technology today. Along the way, he also published a landmark essay, "The Correlation...