if other circumstances should not render that route inconvenient, and the more so as it was the standard meridian to which he referred all the longitudes of his survey.
From thence there will be nothing to delay your progress towards that part of the western coast where Captain Fitzroy's late survey terminated. Unfortunately no account of his concluding operations has yet arrived, but by a comparison of dates it does not appear that there could have been time to examine much of the coast of Chili, to the northward of Valparaiso, or even to complete it down to that port. This question must be decided, because at no great distance to the southward lie the shoals of Topocalmo, where an American ship was wrecked, and which, if they have not been satisfactorily laid down by him, and their connexion with the shore examined, must not be neglected by you.
It is, however, probable that at Valparaiso you will be able to obtain such information on that subject, as may help to guide your movements; but if not, there will be little danger of repeating any part of his work if you commence yours at Coquimbo, leaving the interval to be hereafter effected, when the return of the Beagle, or the arrival of her despatches, shall enable me to define more exactly the point at which the great work assigned to you by their Lordships ought to begin.
Of that extensive region which your work is to comprehend, we are at present best acquainted with the southern portion, including Chili and Peru. Yet of those long and populous coasts, excepting the ports of Guayaquil and Callao, our whole knowledge is derived from two Spanish charts, on the limited scale of one inch to twenty-eight miles ; and it appears from Captain Fitzroy's recent examination of the large island of Chiloe, and of the intricate gulf of Chonos, that those charts
