3 = signature.
3 = End of word.
33 = End of sentence.
333 = End of message.
22, 22, 3 = I understand.
The complete number opposite each letter or numeral stands for that letter or numeral.
Example: The signal sent by Commodore Schley's flagship "Brooklyn" that memorable 3d of July-- T H E E N E M Y' S F L E E T 2, 122, 12 3 12, 11, 12, 1221, 111, 212 3 2221, 221, 12, 12, 2, 3 L, RLL, RL D RL, RR, RL, RLLR, RRR, LRL D LLLR, LLR, RL, RL, L, D I S C O M I N G O U T O F 1, 212 3 121, 21, 1221, 1, 11, 2211 3 21, 112, 2 3 21, 2221 R, LRL D RLR, LR, RLLR, R, RR, LLRR D LR, RRL, L D LR, LLLR H A R B O R.
122, 22, 211, 2112, 21, 211, 333.
RLL, LL, LRR, LRRL, LR, LRR, DDD.
R = Right = 1.

L = Left = 2.

D = Drop = 3.
NIGHT SIGNALLING.
The lights in the Ardois system--named after its inventor--sometimes called "shroud lights," are placed well up on the foremast.

They are red and white electric bulbs.

There are four of each placed in a line one above the other, in groups of two--- a red and white bulb together.
Unlike the "wigwag" system, the whole letter is shown at once.
The code is the same as the "wigwag." One is indicated by a red light, two by white, and three by the combination, white, white, red and white.
Both systems may be mastered very easily by a little painstaking practice, and much amusement may be had through the mystification of those who do not understand it.