418 
APPENDIX. 
on board ; you have ten months' provisions on board for the crew, and 
an ample supply of warm clothing, antiscorbutics, preserved meats, 
&c, in the event of detention, which will be expended in the most 
judicious manner. 
Wishing you a safe and successful cruise, 
I am, &c, 
Charles Wilkes, 
Commanding Exploring Expedition. 
P. S. You will, if possible, obtain from Deception Island a self- 
registering thermometer, said to have been left some time since on 
the point of the cove. 
To Lieut. Wm. L. Walker, 
In cJiarge of Tender Flying-Fish. 
XXVIII. 
GENERAL INSTRUCTIONS, FOR BOAT DUTY, SURVEYING, ETC. 
Immediately after anchoring in position, you will hoist your dis- 
tinguishing pennant, keeping it up till every thing is done, such as, 
distance measured, astronomical bearings taken on one of the vessels, 
the angle between her and the others; also, angles on any thing 
remarkable on shore, such as headlands, flag or signal staves, huts, 
trees, &c. When ready to change your position, haul down your 
distinguishing pennant, and when ready to measure the base or dis- 
tance by sound, which is the first thing to be done after you are in 
position, hoist your ensign at the fore; as soon as all the vessels have 
answered, you will dip it and fire in a few seconds, run up the ensign 
again, and repeat firing three times. 
To communicate the elapsed time to this vessel, hoist the distin- 
guishing pennant of the vessel whose distance is to be shown, and 
with it the "number" indicating the number of seconds; the quarter, 
half, or three-quarters, may be designated by hoisting the first, second, 
and third repeaters under all, thus— the third repeater under No. 
18, would signify eighteen and three-quarter seconds of time. It will 
be seen, therefore, that when it is necessary to repeat a number, one 
of a similar denomination must be used, as another signification is 
given to the repeaters. 
