Mr. SULZER. Is there any government that grants a patent or copyright for more than fifty years that you know of? Mr. WALKER. Not that I know of. Fifty years would be altogether excessive for any patent. The longest period that could possibly be vindicated by argument for a patent would be twenty years. Mr. BONYNGE. How about copyright? Mr. WALKER. I wish I could argue the matter; but I hold that all original works ought to be copyrighted for a hundred years, and all derivative works, such as dictionaries and encyclopedias, for fifty. Mr. BONYNGE. What is the longest period granted by any government, that you recall, for a copyright? Mr. WALKER. I can not speak as to that with certainty. Mr. SULZER. Fifty years? Mr. WALKER. The nations are numerous. Now, I must come to another point, section 23, in respect of the damages that may be recovered. Section 23 begins as follows: That if any person shall infringe the copyright in any work protected under the copyright laws of the United States by doing or causing to be done, without the consent of the copyright proprietor first obtained in writing, any act the exclusive right to do or authorize which is by such laws reserved to such proprietor, etc. The trouble with that is that it makes the man who does the thing an absolute infringer unless he can show a consent in writing; and that repels the whole doctrine of implied licenses and equitable estoppel, which two doctrines are found to be absolutely indispensable to the administration of justice in patent cases, and heretofore in copyright cases. The idea that there can be no answer to an infringement suit for a copyright except a written license is new in this statute. It has never been in any copyright law before, and it would work havoc with justice, because it would enable the wilfully malicious copyrighters to mislead men into unwitting infringement, and then pounce on them with an infringement suit, and then, when they set up equitable estoppel or an implied license, say, "Equitable estoppel and implied license do not go in this statute. You must show a written license." Words can not express how badly that would work. Again, in subdivision B, this man is-- to pay to the copyright proprietor such damages as the copyright proprietor may have suffered due to the infringement, as well as all the profits which the infringer may have made from such infringement.