after stating the case, delivered the opinion of the court.
The case presented by the foregoing facts is one not free from difficulties. The government has used .the invention of
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Mr. Clark and has profited by such use. It was an invention of value. The claimant and appellant is the owner of such patent, and has never consented to its use by the gbvernment. From these facts, standing alone, an obligation on the part of the government to pay naturally arises. The government has no more_ po_wer to appropriate a man’s property invested in a patent than it has to take his property invested in real esíaté ; nor does the mere fact that an inventor is at the time of his invention' in the employ of the government transfer to it any title to, or interest in it. An employé, performing all the duties assigned to him in his department of service, may exercise his inventive faculties in any direction he chooses, with tl^e assurance that whatever invention he may thus conceive and perfect is his individual property. There is no difference between the government and any other employer in this respect. But this general rule is subject to these limitations. If one is employed to devise' or perfect an instrument, or a paeans for accomplishing a prescribed result, he cannot, after Successfully accomplishing the work for which he was employed, plead title thereto as aga.inst his employer. That which he has been employed and paid to accomplish becomes, when accomplished, the property of his employer. Whatever rights as an individual he may have had in and to his inventive powers, and that which they are able to accomplish, he has sold in advance to his employer. So, also, when one is in the employ of another in a certain line of work, and devises an improved method or instrument for doing that work, and uses the property of his employer and the services of other employes to develop and put in practicable form his invention, and explicitly assents to the use by his employer of such invention, a jury, or á court trying the facts, is warranted in finding that he has so far recognized the obligations of service flowing from his employment and the benefits resulting from his use of the property, and the assistance of the coemployes, of his employer, as to have given to such employer an irrevocable license to use such invention. The case of
M'Clurg
v.
Kingsland,
Affirmed.
