A Journey in Other Worlds by John Jacob Astor IV

Two days later, on the western horizon, they beheld the ocean. Many of the streams whose sources they had seen when they crossed the divide from the lake basin, and whose courses they had followed, were now rivers a mile wide, with the tide ebbing and rising within them many hundreds of miles from their mouths. When they reached the shore line they found the waves breaking, as on earth, upon the sands, but with this difference: they had before noted the smallness of the undulations compared with the strength of the wind, the result of the water's weight. These waves now reminded them of the behaviour of mercury, or of melted lead when stirred on earth, by the rapidity with which the crests dropped. Though the wind was blowing an on-shore gale, there was but little combing, and when there was any it lasted but a second. The one effort of the crests and waves seemed to be to remain at rest, or, if stirred in spite of themselves, to subside.

When over the surface of the ocean, the voyagers rose to a height of thirty thousand metres, and after twenty- four hours' travelling saw, at a distance of about two hundred miles, what looked like another continent, but which they knew must be an island. On finding themselves above it, they rose still higher to obtain a view of its outlines and compare its shape with that of the islands in the photographs they had had time to develop. The length ran from southeast to northwest. Though crossed by latitude forty, and notwithstanding Jupiter's distance from the sun, the southern side had a very luxuriant vegetation that was almost semi-tropical. This they accounted for by its total immunity from cold, the density of the air at sea-level, and the warm moist breezes it received from the tepid ocean. The climate was about the same as that of the Riviera or of Florida in winter, and there was, of course, no parching summer.