JAMES R. GIBSON
On the world map of the middle of the eighteenth century, the Pacific coast of North America, with the exception of New Spain, was one of the few shorelines that remained unknown to nonnative peoples; the only longer uncharted coasts were those of the Arctic and Antarctic. Indeed, the entire North Pacific was so unknown that when Jonathan Swift published Gulliver's Travels in 1726, he confidently set the imaginary and dilapidated island empire of Laputa (including Balnibarbi, Glubbdubdrib, and Luggnagg) off the coast of Japan and made Brobdingnag, the mythical land of giants, a six-thousand-mile-long peninsula of California. This anonymity was simply the result of the relative locations of the imperial powers and the directions of their colonial expansion. Britain, Holland, Portugal, and Spain had expanded overseas from western Europe to the Atlantic margins of the Americas and Africa and to the Indian Ocean shores of Africa and Asia first, leaving the more forbidding North Pacific and Arctic coasts of Asia and North America for last. By the eighteenth century, only Britain and France, unlike Holland, Portugal, Russia, and Spain, lacked convenient springboards for Pacific exploration; all ports of call in South America were controlled by Portugal or Spain, the Cape Horn entrance (the Drake Passage) was difficult, and Holland and Spain controlled the western approaches of the East Indies and the Philippines.
The chief technical obstacle was an accurate method of determining longitude. The water clocks and even the later pendulum clocks were useless on a rolling ship; timekeeping with a half-hour sandglass was unsatisfactory because of premature upturning by a lazy watch; checking the log against the sun at midday was not always permitted by the weather; and dead reckoning (the measuring of courses and distances run) was also inaccurate, especially in the huge expanse of the Pacific. In the absence of trustworthy data, rough indications of the proximity of land were used: floating debris such as branches and seaweed; bird flights; changing water