To be Patentable, the invention must be new, unused and unknown before, and useful.
"Studies in Civics"
James T. McCleary
Therefore, after a careful examination of these cases, it is no criticism of the courts to say that both sides have found abundant and about an equal amount of authority to sustain their respective contentions, and, as a result, counsel have submitted, in briefs, a sum total of 225 closely printed pages, in which they have clearly, yet, almost to a mathematical certainty, demonstrated on the one side that this Schrader machine is new and Patentable, and on the other that it is old and not so.
"Edison, His Life and Inventions"
Frank Lewis Dyer and Thomas Commerford Martin
In granting patents to foreigners the proper course for this country to follow is to give the same advantages to foreigners here that the countries in which these foreigners dwell extend in return to our citizens; that is, to extend the benefits of our patent laws on inventions and the like where in return the articles would be Patentable in the foreign countries concerned-where an American could get a corresponding patent in such countries.
"Complete State of the Union Addresses from 1790 to the Present"
Various