On the 13th of November I sailed from Macao for Singapore, with fine weather, and the wind from north-east to east-north-east. On the 19th, Cape Varella was seen at noon, bearing north-west about thirty miles distant, and with continued breezes from the north-east and north-north-east: saw Pulo Sapata at noon of the 20th, the bearing being west half-south, about eighteen miles distant. On the 22nd, after squally weather, a hawk was for several mornings seen about the ship, occasioning the fowls to make a great noise at his presence; we were then in latitude 6° 34′ north, and longitude 106° 28′ east. On the 24th at noon, Pulo Aor was in sight, bearing south-west half-west; Pulo Pisang, west by south; Pulo Tinian, west half-north by compass. All these islands were elevated, and densely wooded. On the 26th we passed _Pedro Blanco_, a reef of rocks some distance above the water, and situated in about the centre of the straits; a large number of birds, apparently terns, were about them. I had much doubt in my mind, whether the white appearance of the upper surface of these rocks was the effect of the dung of birds, but rather conjectured, in the absence of ocular proof, that it was of a calcareous nature. Observing a group of rocks not far distant from the settlement of Singapore, exhibiting the same white appearance on the surface above water as the Pedro Blanco, I determined to visit them for the purpose of examining their structure; on the evening of the day on which I observed it, I went out in a boat with some friends, but a very heavy swell prevented the attainment of my object at this time. The Malays in the boat, when they heard what I wished to ascertain, declared it to be produced by the first-mentioned cause; but on the following morning I succeeded in getting upon it, when my previously formed opinion was confirmed, by finding the upper surface calcareous, at some parts more or less discoloured. The formation of the rock was secondary, being of a red sandstone, and in many specimens, which I broke off, I observed a very minute line of sandstone, running through the calcareous substance; although other parts of this rock were also calcareous, yet they had not a white appearance, from being covered and discoloured by marine conferva and minute crustaceous animals, to such an extent as to entirely lose their white appearance unless broken; and the marine animals being constantly in the other rocks washed by the sea, which the high and white rock was not, caused a still further increase of marine weeds, &c. upon them. I collected some excellent specimens, showing the two different strata very distinctly. About ten P.M. of the 26th, we anchored in Singapore roads; and upon the following day I landed and took up my residence, during my stay at the settlement, with my friend Mr. Boustead.