_East of Greenwich_] NOTICE EXPLANATORY OF A CHART OF THE SOUTH SIDE OF THE GULF OF PE-CHE-LEE, YELLOW SEA. [Sidenote: First meridian used in constructing the chart.] In constructing this chart, I have assumed the longitude of the fort at the mouth of the Pei-ho to be 117º 49' east of Greenwich, or 11' west of the place where the squadron lay at anchor. From this the difference of longitude was measured by two chronometers. The latitudes were ascertained by frequent observations of the stars, as well as of the sun. [Sidenote: Aspect of the south and south-west coasts.] [Sidenote: Soundings.] The coast on the south and south-west sides of this Gulf is very low, resembling, in this respect, the shore at the entrance of the Pei-ho, or Pekin river, where it is uniformly low and sandy; occasionally a few houses are to be seen, and also square mounds or buildings like forts, but generally, a low white beach is all that can be discovered. The coast is not visible till within about three leagues distance, and the eye elevated eighty feet from the sea, which is the height of the Lyra's foretop-gallant yard. The depth of water when the land first came in sight, was generally five fathoms; at some places only four fathoms, and at the very bottom of the Gulf, it could not be discerned till in three and a half fathoms. It may be said generally, that at ten miles distance the soundings are from four and a half to six fathoms; at twelve miles, from six to eight fathoms. There is a wonderful uniformity in the depth from the Pei-ho round to the south-east corner of the Gulf; the bottom is mud, sometimes a little gritty, particularly towards the southern parts. [Sidenote: Colour of the water.] The colour of the water was mostly of the same dirty yellow or green which was observed off the Pei-ho, but we did not observe any red coloured water, as was frequently noticed at that place; at the bottom of the Gulf, indeed, there were several changes in the colour of the water, accompanied by long lines of foam, indicating, it would seem, the vicinity of a great river. [Sidenote: Tides on the western side of the Gulf.] On the west side of the Gulf the ebb tide runs to the south-east by south, and the flood north-west by west; the periods are very regular, being generally about six hours: they vary, however, in rapidity. As we anchored on the flood we were enabled to measure its velocity; as we got deep in the Gulf it decreased: at the Pei-ho it frequently ran two and two and a half knots, but far south it was sometimes hardly perceptible; it is worthy of notice, too, that the perpendicular rise and fall decreased from ten feet off the Pei-ho, to one, or at most two feet, in the bottom of the Gulf. [Sidenote: Bottom of the Gulf.]