Formosa was visited in April, northern Japan in May, and the investigation of the north-eastern coasts of Asia occupied until October.

A passage in a letter from Laperouse to Fleurieu is worth quoting for two reasons.  It throws some light on the difficulties of navigation in unknown seas, and upon the commander’s severe application to duty; and it also serves to remind us that Japan, now so potent a factor in the politics of the East and of the whole Pacific, had not then emerged from the barbarian exclusiveness towards foreigners, which she had maintained since Europe commenced to exploit Asia.  In the middle of the seventeenth century she had expelled the Spaniards and the Portugese with much bloodshed, and had closed her ports to all traders except the Chinese and the Dutch, who were confined to a prescribed area at Nagasaki.  Intercourse with all other foreign peoples was strictly forbidden.  Even as late as 1842 it was commanded that if any foreign vessel were driven by distress or tempestuous weather into a Japanese port, she might only remain so long as was necessary to meet her wants, and must then depart.  Laperouse knew of this jealous Japanese antipathy to foreign visitors, and, as he explains in the letter, meant to keep away from the country because of it.  He wrote:—­

“The part of our voyage between Manilla and Kamchatka will afford you, I hope, complete satisfaction.  It was the newest, the most interesting, and certainly, from the everlasting fogs which enveloped the land in the latitudes we traversed, the most difficult.  These fogs are such that it has taken one hundred and fifty days to explore a part of the coast which Captain King, in the third volume of Cook’s last voyage, supposes might be examined in the course of two months.  During this period I rested only ten days, three in the Bay of Ternai, two in the Bay de Langle, and five in the Bay de Castries.  Thus I wasted no time; I even forebore to circumnavigate the island of Chicha (Yezo) by traversing the Strait of Sangaar (Tsugaru).  I should have wished to anchor, if possible, at the northern point of Japan, and would perhaps have ventured to send a boat ashore, though such a proceeding would have required the most serious deliberation, as the boat would probably have been stopped.  Where a merchant ship is concerned an event of this kind might be considered as of little importance, but the seizure of a boat belonging to a ship of war could scarcely be otherwise regarded than as a national insult; and the taking and burning of a few sampans would be a very sorry compensation as against the people who would not exchange a single European of whom they were desirous of making an example, for one hundred Japanese.  I was, however, too far from the coast to include such an intention, and it is impossible for me to judge at present what I should have done had the contrary been the case.