SIGNALLING WITH THE HELIOGRAPH 177 



It will often be found very advantageous to substitute for the conventional sig- 

 nals given above, the following : 



End of word 1 extra long flash (about three times the 



length of a dash). 



End of sentence 2 extra long flashes. 



End of message 3 extra long flashes. 



Although this slows up the transmission it is a great help to poorly trained 

 operators, and is particularly valuable when sending code messages where it is 

 impossible to make out the proper spacing from the context. 



This code is used for signalling with the heliograph by the British and Canadian 

 military forces and will probably be the one best adapted for use in Canada in forest-, 

 protection communication. It is adapted not only to visual but also to electric tele- 

 graphic signalling and radio work. 



3 MYER CODE 



This code was formerly used by the United States Army for visual signalling and 

 is still employed in certain districts by the United States Forest Service. In this code 

 there are three elements, generally designated, 1, 2, and 3. All letters are made up of 

 combinations of 1 and 2; 1 being a short flash; 2, two short flashes in quick succes- 

 sion. 3 is a long flash, like a dash of the International Morse code, and is used to 

 indicate certain pauses and in conventional signals. This code has certain advantages 

 for heliograph work, although it has now been pretty generally abandoned in favour 

 of the more generally useful International Morse code. 



MYER CODE ALPHABET 



A 22 O 21 



B 2112 P 1212 



C 121 Q 1211 



D 222 K 211 



E 12 S 212 



F 2221 T 2 



G 2211 U 112 



H 122 Y 122-2 



I 1 W 1121 



J 112-2 X 2122 



K 2121 Y Ill 



L 221 Z 2222 



M 1221 Question 1112 



N 11 



NUMERALS 

 1 1111 6 2211 



2 22'22 7 12>22 



3 1112 8 2111 



4 2221 9 1221 



5 . . 1122 2112 



ABBREVIATIONS 



A After T The 



B Before U You 



C Can Ur Your 



H Have W Word 



N Not Wi With 



K Are Y Yes 



7921112 



