Opinion of the Court
Park, Edison and a team toiled to improve upon the prevailing method of incandescent lighting, which tended to employ carbon filaments. 159 U. S., at 471–473. The problem with carbon filaments was that they disintegrated rapidly. In a sense, “carbon contained in itself the elements of its own destruction.” Id., at 471. Seeking an alternative, Edison tinkered for a time with platinum, but it was expensive and difficult to bring to the point of incandescence without melting. Stross 78, 82. Eventually, Edison dispatched men across the globe to collect specimens of bamboo. Id., at 109–110. One sample from Japan worked brilliantly because “[its] fibres [ran] more nearly parallel than in other species of wood.” 159 U. S., at 473. Satisfied, Edison arranged to have a Japanese farmer supply all of the bamboo he would ever need. Stross 110.
But there was a catch. William Sawyer and Albon Man had obtained a patent for an “ ‘electric lamp’ ” with an “ ‘incandescing conductor’ ” made of “ ‘carbonized fibrous or textile material,’ ” which they claimed was an improvement over conductors made of “ ‘mineral or gas carbon.’ ” 159 U. S., at 466, 468. Sawyer and Man’s patent had not won them commercial success. They had designed a lamp with a conductor made of carbonized paper, but the lamp proved defective and quickly fell out of use. See id., at 471–472. Still, their failure did not stop them from seeking to share in some of Edison’s success. Sawyer and Man alleged that Edison’s lamp infringed their patent because it “made use of a fibrous or textile material, covered by the patent.” Id., at 471. What was that offending material? Bamboo.
This Court sided with Edison. It held that Sawyer and Man’s patent claimed much but enabled little. “Sawyer and Man supposed they had discovered in carbonized paper the best material for an incandescent conductor.” Id., at 472. But “[i]nstead of confining themselves to carbonized paper, as they might properly have done, and in fact did in their third claim, they made a broad claim for every fibrous and
