This original Progress Chart of the Survey of the Northern & North Western Lakes, dated July 1, 1873, shows the progress of the establishment of the telegraphic longitudes by the Engineering Department of the U.S. Coast Survey. This information would eventually provide more accuracy in the development of the new navigational charts, as well as, correcting the old ones. This chart is tinted and in good condition. The framing is done to conservation standards with an attractive burl wood frame.