[Ships of the line during the 1700s] required for the hull some two thousand oak trees, averaging a hundred years old, and England was cutting down her oaks much faster than she was replacing them. There was particular difficulty in securing great trees for the massive sternposts, and crooked timbers for the sixty or seventy ribs of the ship. For the planking of the bulging yellow sides England had to send to Danzig, Riga, or other ports of the Baltic, whence also, from Polish forests, came the masts of middling size. The little spars had general grown on some Norwegian mountainside; but for the great lower masts, anywhere from two feet to forty inches in diameter, the royal navy depended upon colonial pines in New Hampshire and Maine. More than once, as we shall see, the navy was to be handicapped when its supply of masts or oak was curtailed.
(from A History of England and the British Empire)