In 1847, Thomas Thatcher acquired the rights to the Thomas Chandler mortiser patent for New York City. He started selling them, and sometime after February of 1848 had acquired a partner, henceforth operated under the name Burt, Thatcher & Co. The latest evidence for their continued operation is from October of 1848.

Information Sources

• Sixth Annual Report of the American Institute, March 1848, including the results of the 1847 Fair: Thomas Thatcher, New York, for a morticing and tenoning machine. Silver medal.
• We learned of Thomas Thatcher from a correction in the 1847-11-13 Scientific American. "Morticing Machine. In describing this machine in last weeks Scientific American, we made a mistake in saying that Thomas Chandler, was proprietor of it for this city, Brooklyn, and Essex Co., N. J. Thomas Thatcher is the proprietor, office No. l53 Greenwich street, this city. This indicates that he sold, and probably manufactured, the Chandler mortiser. During that time of expensive transportation, many patent-holder licensed others to make and sell their inventions outside the inventor's home territory.
• Ad in the 1848-02-19 issue of Scientific American:

  CHANDLER'S PATENT MORTICING MACHINE. This is the only machine ever offered to the public that will do the work required in so perfect a manner in so short a time. It is the only machine that will clear the chips from the mortice, which is a great improvement over all other machines. It will work on any kind of wood and can be operated with any kind of power. It can be applied to framing large timber as well as small, and is not liable to get out of order. It took the first premium at several Fairs last autumn and a medal from the American Institute. It can be seen at 153 Green st., New York, where all orders will be executed with dispatch.
  THOMAS THATCHER.
  N. B. A partner wanted with a capital, to embark in the business.

• Seventh Annual Report of the American Institute, March 1849, including the results of the 1848 Fair: Burt, Thatcher & Co., 153 Greenwich-street, for a power morticing machine. (Silver medal having been before awarded.) Diploma.