Issued, May 1888, F.M. Thorn, Superintendent. Verified: B.A. Colonna, Assistant in charge of Office ; Triangulation [and topography] by C. Rockwell, Assistant ; Hydrography by C. Rockwell and J.J. Gilbert, Assistants ; Astronomical observations by W. Eimbeck and G. Davidson, Assistants ; Magnetic Observations by J.S. Lawson, Assistant ; Verification of Hydrography by Lieut. Comdr. W.H. Brownson, U.S.N. Inspector of Hydrography ; ...reduced drawing of Topography by H. Lindenkohl ; ...of Hydrography by A. Lindenkohl ; Outlines and Topography [engraving] by H.C. Evans, lettering by A. Petersen and F. Courtenay, Sand by H.C. Evans, Title and Notes by H.M. Knight. Coordinates approximate (Greenwich meridian) Depths shown by soundings and gradient shading (in low water areas); relief by contours and spot heights Variation compasses Bar scales in statute miles, nautical miles, kilometers Buoy legend, tidal and explanatory notes, river lights table, latitude and longitude of Saint Helen (Church) Shows waterways, vegetation, topography, islands, roads, railroads, various buildings, divisions of land "No. 641c," "Plate no. 1999," "Electrotype Copy No. 1..."