mode of applying it in such a
clear, intelligible manner that those who are "skilled in the art"
can, without other aid, use the invention. Nothing should be left to
experiment. The phrase "skilled in the art" means persons of ordinary
skill. Whether a description is clear, exact and sufficient is a
question for the jury whenever it is a matter of legal contention.

In describing an improvement the same rule is applied. The description
should show clearly the nature of it. The description should
distinguish between the old and the new. "A description in a patent
for an improvement is sufficient if a practical mechanic acquainted
with the construction of the old machine in which the improvement is
made, can, with the aid of the patent and diagram, adopt the
improvement." If an inventor intentionally conceals facts or misleads
the public by an erroneous description, his patent is void.

Concerning the claim or claims with which the inventor concludes his
specification many questions have arisen. First, the claim must be
clearly stated so that the public may know what it is. The claim
should not be too broad. Several claims may be made, but they should
not be varying phraseology for the same thing. They should state the
physical structure or elements of mechanism by which the end or result
is produced.

The inventor must make oath that he believes himself to be the
original and first inventor, that he does not believe that the thing
was ever before known or used, and as to his citizenship. If dead or
insane, the oath must be made by his executor, administrator, or other
representative. After the application is granted another fee of twenty
dollars must be paid.

The commissioner of patents must make an examination for the purpose
of deciding whether a patent may be granted or allowed. This
examination is made by an examiner, whose decision, however, is not
conclusive and may be set aside by the commissioner. The patent office
is not confined to technical evidence in rejecting applications, but
may base its action on anything disclosing the facts relating to the
matter.

When objection is made to the form of the application, an amendment
may be made by the applicant or his attorney to correct the error; and
this may be done at any time prior to the entry by the first examiner
of a final order of rejection, and within one year from the date of
the preceding action by the patent office.

When two parties apply for a