200 cook's first voyage august, 



Islands, where, at low water, there are but three 

 fathom : for a more particular knowledge of this 

 strait, 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 possi- 

 ble 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 and 22, 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 lati- 

 tudes and longitudes of all, or most of the principal 

 head-lands and bays, may be confided in, for we sel- 

 dom failed of getting an observation once at least 

 every day, by which to correct the latitude of our reck- 

 oning, 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 calcu- 

 lating 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 de- 

 pended upon within half a degree, which is sufficient 

 for all nautical purposes. Ifi therefore, observing 

 and calculating were considered as necessary quali- 



