Ad for Edison's isolated electric power-plants for incandescent lighting systems. From Electrical World, 1887.
National Museum of American History, SI negative # 80-18694

The "Card to the Public" reads:
     "The Edison Electric Light Company having instituted suits on its patents, must decline to substitute the advertising columns of the press for the courts for the purpose of legal interpretation. Mr. Edison's carbon filament patent of 1879 covers broadly the modern incandescent lamp. The claim that this patent has ever been in litigation in the United States Patent Office is absolutely false. In Germany and England, this fundamental patent has finally prevailed against all infringers, thus establishing the fact that Mr. Edison's great invention has been nowhere anticipated; ergo, a like result must follow in the United States. The straining and distorting of these facts, together with the violent effort to interweave with them certain minor and irrelevant cases for the purpose of fraudulently posing before the public as joint heirs with Mr. Edison in the fruits of these patent decisions, only indicate the dire extremity of those who are thus gradually becoming environed by due process of law."

This is an interesting read for anyone studying logic. For example: declining to use "the advertising columns of the press" instead of the courts for "legal interpretations" -- and then proceeding to do just that.

Edison spent a great deal of time and effort in court defending his patents. The major "final" decision which upheld his electric lamp patents came in 1892, thirteen years after the invention.