Our progress for this twenty-four hours was not such as would delight the heart of a steam-yachtsman, for our difference of latitude was precisely nothing, and we made twenty-five miles of westing, which would indicate a current. The heat, of course, is great, and also the oppressiveness, everything being indescribably sticky and soft. The temperature of the sea has risen to correspond with that of the air, both standing at about eighty-four degrees; severe rain-squalls with little or no wind necessitate oil-skins on deck, for if your clothes get wet they will be hours drying in this weather; indeed, they will not dry at all, unless you put them on, when the heat of the body evaporates the moisture. As we have been several days now in very hot weather, we have had plenty of opportunity of comparing the cabins of a wooden and an iron ship in the tropics. As might have been expected, that of the “Higgins” is cooler than that of the iron “Mandalore”; but the difference is surprisingly little, not more than two or three degrees. The principal disparity we notice at night, as the “Mandalore’s” top-sides used to retain the heat of the sun for so long a period that it was frequently two o’clock in the morning before the temperature fell perceptibly. The thermometer now in our room stands at about 85° day and night as against 87° and 88° in the other ship. Yesterday we caught a dolphin. It was a true dolphin, _delphinus delphis_, a mammal, the bottle-nose of sailors; seafaring people giving the name to a small beautifully-colored fish, _coryphœna hippuris_, which isn’t a dolphin at all.