Fascinating navigational chart, copyrighted in Massachusetts and created by John G. Fish & Nelson Mullin, Proprietors.
The chart notes that "The Rules in Bowditch's or Thoms' Navigator conform to this . . . "
We note that the example at the top right shows instructions "To find bearing and distance of Block Island."
We have been completely unable to locate any information regarding the partnership of Fish and Mullin. We do note that a seaman by the name of John G. Fish is credited with "inking on scrimshaw" during a voyage from Boston to San Francisco in 1868.
We also note that a Nelson Mullin is noted as the postmaster of North Haven, Maine, in 1866 and a U.S. Deputy Customs Collector in 1879.