Islands, where at low water there are but three fathom:  For a more particular knowledge of this streight, and of the situations of the several islands and shoals on the eastern coast of New Wales, I refer to the chart where they are delineated with all the accuracy that circumstances would admit; yet, with respect to the shoals, I cannot pretend that one half of them are laid down, nor can it be supposed possible that one half of them should be discovered in the course of a single navigation:  Many islands also must have escaped my pencil, especially between latitude 20 deg. and 22 deg., where we saw islands out at sea as far as an island could be distinguished; it must not therefore be supposed, by future navigators, that where no shoal or island is laid down in my chart, no shoal or island will be found in these seas:  It is enough that the situation of those that appear in the chart is faithfully ascertained, and, in general, I have the greatest reason to hope that it will be found as free from error as any that has not been corrected by subsequent and successive observations.  The latitudes and longitudes of all, or most of the principal head-lands and bays, may be confided in, for we seldom failed of getting an observation once at least every day, by which to correct the latitude of our reckoning, and observations for settling the longitude were equally numerous, no opportunity that was offered by the sun and moon being suffered to escape.  It would be injurious to the memory of Mr Green, not to take this opportunity of attesting that he was indefatigable both in making observations and calculating upon them; and that, by his instructions and assistance, many of the petty officers were enabled both to observe and calculate with great exactness.  This method of finding the longitude at sea may be put into universal practice, and may always be depended upon within half a degree, which is sufficient for all nautical purposes.  If, therefore, observing and calculating were considered as necessary qualifications for every sea officer, the labours of the speculative theorist to solve this problem might be remitted, without much injury to mankind:  Neither will it be so difficult to acquire this qualification, or put it in practice, as may at first appear; for, with the assistance of the nautical almanack, and astronomical ephemeris, the calculations for finding the longitude will take up little more time than the calculation of an azimuth for finding the variation of the compass.[87]

[Footnote 87:  Reference is made above to Cook’s large chart, which of course could not be given here with advantage corresponding to the expence of engraving it.  This omission is of less moment, as the chart that accompanies the work is quite sufficient for general readers; and as any additional one that may be afterwards given, must derive much of its value from the labours of Cook.  Important aids have been afforded the navigator since the date of this publication; and the