Merchants made great profit on cargoes from China, and speed was a prime element in the value of a ship.

In 1840 the discovery of gold in California added a new demand for ocean shipping; the voyage around the Horn, already common enough for whalemen and men engaged in Asiatic trade, was taken by tens of thousands of adventurers.

Then came the news of gold in Australia, and again demands were clamorous for more swift American ships.

All nations of Europe were buyers at our shipyards, and our builders began seriously to consider whether the supply of timber would hold out.

The yards of Maine and Massachusetts sent far afield for white oak knees and pine planking.