A slight pause is made between each signal.
The following conventional signals are authorized, using the Morse alphabets:
| End of word | one front. |
| End of sentence | two fronts. |
| End of message | three fronts. |
TO SIGNAL WITH THE HELIOGRAPH OR FLASH LANTERN.
The dot is made by pressing down the key of the shutter and immediately releasing the same.
The short dash is made by pressing down the key and holding it down for a period equal to two dots.
The long dash ("L") is made by holding down the key for a period equal to three dots while the longer dash (naught) requires the key to be held down for a period equal to four dots.
The space is made on the heliograph as in ordinary telegraphy by the absence of any signals for a period equal to the time of one dot.
On the heliograph the letter "C" is made as follows: Short flash, short flash, interval, short flash.