Longitude from sixty sets of lunar distances, of which the individual results are given in Table VIII. of the Appendix No. I. to this volume, 155° 18' 50.5" E.
The longitude of the bank, as given by Earnshaw's No. 520 on Aug. 28, eleven days after the shipwreck, was 155° 4' 14.6" with the Port Jackson rate, or 14' 35.9" less than the lunar observations. In laying down the Porpoise's track on the chart, this error has been corrected by an equal proportion, according to the time of each observation for the longitude.
Mr. Flinders deduced the variation of the compass from observing the sun's magnetic azimuth a. m. and p. m., when equal altitudes were taken, and comparing the mean azimuth at corresponding altitudes with the true meridian; this method is probably not the best, and the results from two compasses differed considerably; Walker's compass, marked No. 1, giving 9° 17' east from ten observations, and that marked No. 2, 13° 54' from five observations. The first is undoubtedly the best, though possibly not very correct.
There are here two regular tides daily, and it was high water on the day of full moon at 8h 50' in the morning; the rise was six feet two inches, but the night tide will probably reach to eight, or perhaps nine feet at the height of the springs.
Some account was given of Wreck-Reef Bank before quitting it in the boat, but I had not then acquired a knowledge of the whole extent of the reef. It is about twenty miles long, and from a quarter, to one mile and a half in breadth; and consists of many distinct patches of different magnitudes, the six principal of which are from four to eight or ten miles in circuit. They are separated by channels of one mile to near a league in width; and in the two easternmost I found from 8 to 10 fathoms, and nothing to prevent a ship passing through in a case of necessity. Four of the six larger patches have each a sand bank near the middle, which do not appear to have been lately covered by the tide; and they are now more or less frequented by sea birds, such as noddies, boobies, tropic, and man-of-war birds, gannets, and perhaps some others. Of these four banks, two lie to the west and one to the east of that near which our ships struck; but the eastern bank is the most considerable, and most frequented by birds; turtle also land there occasionally, and this bank was not improperly called Bird Islet, being now covered with coarse grass, some shrubs, and a soil to which the birds are every day making an increase.
Bird Islet being to windward of, and only seven miles distant from our bank, it was frequently visited by the gentlemen during my absence. Besides sea birds of the species already mentioned, they procured many thousand eggs; and also four turtle, of which one weighed 459 pounds, and contained so many eggs, that lieutenant Fowler's journal says no less than 1940, large and small, were counted. These supplies, with shell fish gathered from the reef, and fish, were a great resource, and admitted of a saving in the salt provisions; as the occasional rains, from which several casks were filled, did of their fresh water. The trepang was found on Wreck Reef, and soup was attempted to be made of it; but whether our cooks had not the method of stewing it down, or that the trepang is suited only to the vitiated taste of the Chinese, nothing good was produced
Oats, maize, and pumpkin seeds were planted upon Wreck-Reef Bank, as also upon Bird Islet; and the young plants had come up, and were in a tolerably flourishing state; some of these may possibly succeed upon the islet, but upon the bank it is scarcely to be hoped. The cocoa nut is capable of resisting the light sprays of the sea which frequently pass over these banks, and it is to be regretted that we had none to plant upon them. A cluster of these majestic and useful palms would have been an excellent beacon to warn mariners of their danger; and in the case where darkness might render them unavailing in this respect, their fruit would at least afford some salutary nourishment to the shipwrecked seamen. The navigator who should distribute ten thousand cocoa nuts amongst the numerous sand banks of the Great Ocean and Indian Sea, would be entitled to the gratitude of all maritime nations, and of every friend to humanity. I may be thought to attribute too much importance to this object in saying, that such a distribution ought to be a leading article in the instructions for any succeeding voyage of discovery or investigation to these parts; but it is from having suffered ourselves that we learn to appreciate the misfortunes and wants of others. and become doubly interested in preventing or relieving them. "The human heart," as an elegant author observes, "resembles certain medicinal trees. which yield not their healing balm until they have themselves been wounded."*
[* Le coeur est comme ces sortes d'arbres, qui ne donnent leur baume pour les blessures des hommes que lorsque le fer les a blessés eux-mêmes. Chateaubriant's Génie de Christianisme, Episode d' Attala.]