H6 THE VOYAGE OF H.M.S. CHALLENGER. 



and thence cross the Atlantic to the island of St. Thomas, one of the Virgin Islands, where you would probably 

 arrive about the middle of March. 



From St. Thomas you would go to Bermuda, and in this neighbourhood perhaps a fortnight might be 

 devoted to deep-sea researches. A bank of 11 fathoms has recently been discovered by the 'Ariadne," nearly 

 four miles east of the Kitchen Shoals, which should be further examined. 



Having completed what supplies you require, a line of soundings should be carried to the edges of the bank, 

 in about 600 fathoms, which extends off the American coast in the neighbourhood of Long Island. You would 

 then recross the Atlantic to the Azores, and having completed your researches in the neighbourhood of these 

 islands, you will send to England from Fayal a tracing of the soundings you have obtained since your departure. 



The time of your leaving the Azores for the south will probably be about the 1st July, and if it is 

 convenient to stand to the eastward in the direction of Madeira as far as the 20th meridian, and to ascertain the 

 depth and nature of the bottom there, it will be desirable. Thence a course should be steered for the Cape 

 Verde Islands, where, at St. Vincent, you will be able to replenish fuel, if nothing else, and, should time permit, it 

 would be well to make a new survey of that part of Porto Grande which is used as an anchorage, for the present 

 plan is imperfect and the soundings are not very exact. Leaving the Cape Verde Islands, you will carry a line of 

 soundings between St. Vincent and St. Antonio, and proceed to the southward,, endeavouring to reach the 

 equator between the meridians of 10° and 15° west longitude, working out that region thoroughly from east to 

 west as far as St. Paul's Eocks, or about 30° W. ; hereyou will be in the focus of the great westerly current, and 

 with the calm weather which may be looked for, you will probably be able to set at rest many points of special 

 interest. There is reason, to believe that the depth of the Atlantic equatorial region does not exceed 2000 

 fathoms, which is easily within the reach both of the sounding lead and the dredge^ and it is hoped that by means 

 of anchoring a boat or beacon you will be able to ascertain to what depth the surface current extends, and what 

 are the conditions of the circulation in the lower strata of the ocean. Any reasonable amount of time devoted 

 to this inquiry will be most profitably spent. From St. Paul's Rocks you will proceed to Fernando Noronha, 

 where the ship should be -anchored. This is one of the spots especially recommended by Dr. Hooker as a field 

 for the botanist, and the survey of the anchorage niay be improved with advantage. 



Bahia should.be the next place of call, where you would probably arrive about the middle of September, 

 and, if you are able to obtain the necessary supplies there, it will be well not to call at Rio de Janeiro on your 

 outward voyage, but; after refreshing your crew, to proceed on to the Cape of Good Hope. 



You will probably be able on your way to ascertain the depth of the bank which unites the coast of Brazil 

 and the Abrolhos Shoals with Trinidad and Martin Vas, and. to examine the submarine base of Tristan da 

 Cunha, as welL as to> ascertain its correct elevation, bearing, in mind while on this* ground that none of the 

 soundings shown on the chart of the South Atlantic, with the exception of those obtained by Captain 

 Shortland in the " Hydra," can be- considered reliable. 



You will probably reach the Cape about the 1st November, and. here you should remain a month to refit 

 the ship and for the rest and refreshment of your crew prior to proceeding on the second stage of your voyage 

 into the high latitudes of 'the Southern Ocean. 



Leaving the Cape, Marion and Crozet Islands should be next visited, and subsequently Kerguelen's Land, 

 and it is unnecessary, I am sure, for me to impress upon you the extreme caution and vigilance which will be 

 necessary in navigating this boisterous and little known region with a single ship, even in the middle of the 

 summer season. 



Kerguelen's Land will be a fertile field of exploration in every department of science, and acquires 

 additional interest as one of the stations selected for the observations of the transit of Venus in December 

 1874. What is known of it will be found in the published account of the voyage of Ross, who visited it 

 with the "Erebus" and "Terror" in 1840. A memorandum from the Astronomer-Royal will furnish you 

 "with the nature of the information required for the guidance of the transit party, which will probably proceed 

 there towards the close of 1874, and as it is possible you may not be able to transmit this information to 

 England in time for them before they leave, I should wish you to forward a copy of it to the astronomer at the 

 Cape observatory from the first point you touch at in Australia, for the information of the officer in charge, who 

 will certainly take his final departure from that place. It is desirable that the longitude of the transit station at 



