According to Wikipedia,
Roger Bacon was an American physicist and inventor at the Parma Technical Center of National Carbon Company in suburban Cleveland, Ohio, where he invented graphite fiberss in 1958. Bacon was trying to measure the triple point of carbon—the temperature and pressure where solid, liquid and gas are in thermodynamic equilibrium—in a direct-current carbon arc furnace when he noticed stalagmite-like filaments growing from the vapor phase at lower pressures on the negative electrode. The condensate was embedded with flexible graphite whiskers as much as 5 µm in diameter and 3 cm long. Bacon estimated the production cost of the whiskers at the time as $10 million per pound.