APPENDIX. 397 



XXVI. 



U. S. Ship Vincennes, 

 Orange Harbour, Terra del Fuego, 

 February 22d, 1839. 



Sir, — 



The Sea-Gull, placed under your charge, will be attached to the 

 Porpoise. I cannot impress upon you too strongly the necessity of 

 keeping company, as the safety of the crews of both vessels may 

 otherwise be hazarded ; you will, therefore, use every means in your 

 power to prevent a separation. 



1st. You will keep a strict daily journal of every occurrence relative 

 to your co-operations with the Porpoise. 



2d. A skeleton chart will be furnished you, comprising the latitudes 

 and longitudes in which you will cruise, upon which chart an accurate 

 track will be laid down of her route ; also the position of all land, 

 islands of ice, &c, which may be observed. Astronomical bearings, 

 when the weather will permit, will be preferable for this purpose. 



3d. You will enter also in your journal, the variation of the compass, 

 morning and evening ; sketches of refractions, and minute observations 

 of all phenomena that may be seen ; also, sketches of stratifications of 

 ice, temperature of the water on the weather and lee sides of ice- 

 islands, &c. ; the form and direction of currents, and the apparent 

 formation of the ice ; also the collection and preservation of any 

 specimens of earth or stones that may be discovered on the ice, and 

 the appearance of any halos, auroras australis, &c. 



4th. In the event of parting company, you will rendezvous, first, for 

 the Porpoise, off Cape Melville, George's Island, in latitude 61° 55' S., 

 longitude 58° W., to remain two days ; and, secondly, at and near the 

 coast of the east side of Palmer's Land. You will, in such a case of 

 separation, avoid by all possible means being shut up in the ice, and 

 will, on the probability of such an event, proceed at once to Deception 

 Island, which harbour you will if possible enter, and deposit in a 

 grave formed of stones, on the north side of the entrance of the 

 harbour, information relative to your parting company, &c. ; and you 

 will remain there for orders as long as your safety will allow, and 

 while there you will hunt for and examine a self-registering thermo- 

 meter, left there some time since on the point forming the cove. 



5th. You will give particular attention to the health and comfort of 



2H2 



