MEMORANDUM. 



would be permitted. Where so many unforeseen circumstances 

 may disturb the best-concerted arrangements, and where so 

 much depends on chmates and seasons with which we are not 

 yet intimately acquainted, the most that can be safely done is 

 to state the various objects of the voyage, and to rely on the 

 Commander's known zeal and prudence to effect them in the 

 most convenient order. 



" Applying this principle to what is yet to be done in the 

 Strait, and in the intricate group of islands which forms the 

 Tierra del Fuego, the following list will show our chief desi- 

 derata. 



" Captain King, in his directions, alludes to a reef of half a 

 mile in length, off Cape Virgins, and in his chart he makes a 

 seven fathoms' channel outside that reef ; and still further out, 

 five fathoms with overfalls. Sarmiento places fifty fathoms at 

 ten miles E.S.E. from that Cape; thirteen fathoms at nineteen 

 miles ; and, at twenty-one miles in the same direction, only 

 four fathoms, besides a very extensive bank projecting from 

 Tierra del Fuego, between which and the above shoals Malas- 

 pina passed in thirteen fathoms. In short, there is conclusive 

 evidence of there being more banks than one that obstruct the 

 entrance to the Strait, and undoubtedly their thorough exami- 

 nation ought to be one of the most important objects of the 

 Expedition ; inasmuch, as a safe approach to either straits or 

 harbours is of more consequence to determine than the details 

 inside. 



None of the above authors describe the nature of these 

 shoals, whether rock or sand ; it will be interesting to note 

 with accuracy the slope, or regularity, of the depths, in their 

 different faces, the quality of their various materials, and the 

 disposition of the coarse or fine parts, as well as of what species 

 of rock in the neighbourhood they seem to be the detritus ; 

 for it is probable that the place of their deposition is connected 

 with the very singular tides which seem to circulate in the 

 eastern end of the Strait. 



" Beginning at Cape Orange, the whole north-eastern coast 

 of Tierra del Fuego as far as Cape San Diego should be sur- 



