Washington DC: GPO, 1838. Pamphlet. 101p., terminal blank, disbound 9x6 inch self-wraps held with old binder's cord sunk into the textblock (old stab-holes are empty), quite sound but heavily foxed and has a mild marginal dampstain. Cover leaf is so thickly foxed it is hard to read, mere splotchiness thereafter. The terminal leaf bears a beautifully penned note that "This document includes valuable observations on tides / [initials] / Academy of Nat. Sciences - Philadelphia..June 1838". A reasonably good copy. NB, internal evidence suggests that a line-drawn chart of the surrounding waters was bound with or otherwise attached to this text: chart not available. 25th Congress, 2d Session, Ho. of Reps. War Dept. Doc No. 121.