Cornet" utility patent invented by Henry C. Martin. In 1903 Mr. Martin was issued a patent for his invention from the United States Patent & Trademark Office (USPTO). There were 3 documents on file for this patent. The drawing specification sheet of the patent has been reproduced from original USPTO documents and printed onto parchment paper. This print is sized and ready to install into an 8" x 10" frame. The additional sheets included are printed on 5.50" x 8.50" parchment paper. These accompanying documents describe the scope of this invention in formal terms. The following is an actual excerpt from the patent…

       " This invention relates to certain new and useful improvements in cornets; and it has for its object, among others, to provide a simple and efficient means for instantaneously changing the key of the instrument-say, from B-flat to A"....."of which the following is a specification"…