another. Notwithstanding, the employer is the owner of the patent
and may compel the patentee to transfer it to him. Of course their
respective rights may be changed by agreement. If no agreement exists,
a company that employs a skilled workman to make improvements on its
machinery is not entitled to the patents granted to the workman. Says
Justice Duell: "An employee, performing all the duties assigned to him
in his department of service, may exercise his inventive faculties in
any direction he chooses with the assurance that whatever invention he
may thus conceive and perfect is his individual property. The
company, however, has an implied license to make, use and sell the
invention."

Where a party employs another to assist him in perfecting an invention
the presumption is that the employer is the real inventor of the thing
produced by their joint effort. On the other hand, where a person is
employed to exercise his inventive skill, because he is known to be
the possessor of it, Edison for example, the presumption is in favor
of the employee. Government employees may secure patents on inventions
made by them during their employment, after their relationship has
ceased. The government may have an implied license to use the
invention without any title thereto.

Patents may be issued and reissued to assignees on the application of
inventors. On the death of an inventor before a patent has been issued
to him, his executor or administrator may apply therefor, who takes
the patent in trust for the heirs. A foreign executor or administrator
may make a similar application. He must, however, present a proper
certificate of his authority to act. Likewise, a legally appointed
guardian or conservator of an insane inventor may apply for and obtain
a patent in trust for him.

The inventor must apply to the commissioner of patents for letters
patent which secure to him his invention. The application comprises a
petition, specification, claims, oath, drawings if the nature of the
invention may be thus shown, and a model, when this is required by the
patent office. A fee of fifteen dollars also must be sent with the
papers. The application must be signed by the inventor and two
witnesses.

The specification is the written description of the invention and of
the manner and process of making, constructing, compounding, and
using the invention; whatever it may be. He must describe not merely
the principle of the invention, but the