Since one of the main objects was scientific research, the expedition was provided with a philologist, naturalists, conchologists, mineralogist, botanist, draughtsmen and a horticulturist.
A halt for a week was made at the Madeira Islands, when the ships headed southward, reaching Rio Janeiro late in November.

In January, 1839, they halted at Orange Harbor, Terra del Fuego, and made it their base of operations.

On the 25th of February Lieutenant Wilkes, in the _Porpoise_, accompanied by the _Sea Gull_, started for the South Pole.
On the 1st of March considerable ice and snow were encountered and an island sighted, but the men could not land because of the surf.

The next day the Ashland Islands were discovered and soon after the two vessels reached Palmersland.

The following is the account of Lieutenant Wilkes: "It was a day of great excitement to all, for we had ice of all kinds to encounter, from the iceberg of huge quadrangular shape, with its stratified appearance, to the sunken and deceptive masses that were difficult to perceive before they were under the bow.