Nikola Tesla U.S. Patent 517,900 - Steam Engine Patent Wrapper Page 18

90 SirHon. Conmissioner of Patents, as follows: Room 248. In the Matter of the Application of Nikola Tesla, No. 495,079, Filed December 29, 1893, Engines. New York, March 3rd, 1894. In the above application we now amend Cancel claim 1 and insert: 1. The combination with the cylinder and reciprocating piston and controlling valve of an engine. adapted to be operated by steam or a gas under pressure of an independently controlled engine of constant period operating the said valve, as described. We have emended claim 1 to correct what might be regarded as an inaccuracy but we submit that this is as far as we should be required to go in the direction of amendment suggested by the office. Our claims are to the combination with the controlling valve of an engine of an independent engine of constant period and whether such valve controls the exhaust or whether this latter is independently controlled is immaterial. of course an exhaust of some kind is required, but this is necessarily implied even if not specifically stated. In other words we have named in our claims only those portions of an engine which are directly included. in the combination which constitutes our invention,