Before revision: If, in the Atlantic, ships made the to the west to pick up winds that would bring them back from Madeira, then, he reasoned, by sailing far to the north before heading east, he would pick up trade winds to bring him back to the west coast of North America.
After revision: If, in the Atlantic, ships made the to the west to pick up winds that would bring them back from Madeira, then, he reasoned, by sailing far to the north before heading east, he would pick up the westerlies to bring him back to the west coast of North America.