will, doubtless, pursue this important work, with all the energy in your power, and with all the perseverance consistent with a due regard to the health of your officers and crews.
Where their Lordships have placed such unlimited confidence, it would ill become me to enter too minutely into the lesser pursuits, which are connected with the main object of the coast line ; but there are some detached islands and dangers to which it is proper to advert, and to which it is necessary to call your attention. In crossing from one division of the survey to the other, you might visit and determine the position of the little islands of St. Felix; for though they can offer neither resources nor shelter, yet such insulated specks in the ocean are often useful to the mariner in rectifying his longitude.
A little further to the westward, the brig Cannon, in 1827, discovered a dangerous reef, of half a mile in length, which she called the London Bank, and placed in 27" 6 south, and 92" 16 west, and which it would be useful to verify.
If there be any truth in the report that the earthquake of February has considerably shaken the island of Juan Fernandez, it might be useful to stretch over there, and to examine if any material change has really taken place in the anchorage. Some other extraordinary effects of this earthquake are said to have occurred on the coast of Chili, in permanently elevating part of the shore, and in changing the depth of the adjacent sea. These assertions, if at all true, are probably exaggerated, and you will render a service to geology, by minutely inquiring into the circumstances, and communicating the result without delay.
It may be hoped that Captain Fitzroy has sufficiently
