[ 8. ] 



fignified by the fignal in the line J B : and thus by three lights 

 by night, or three flags by day, may the fymbolical characters 

 of a word or fentence be communicated. However it mufl be 

 obferved, that though the letters bs thus reprefented, their places 

 as they are written in the fymbol do not appear, therefore it 

 will be neceflary that after the lignals fliall have been fuiEciently 

 obferved, they fliould be removed in the order in which they 

 are to be written, fo that the fignal which reprefents the letter 

 at the left hand in the fymbol fliould be firft removed, that of 

 the middle letter is next to be removed, and the fignal of the 

 right hand letter is to be removed lall : or their order may be 

 denoted by the fhape or colour of the flags or lights. Since the 

 triangles J B C, CZ) £ are fimilar, the fi 'es ^C: A B : : EC: 

 ED. whence it follows, that if the dlftance ^C be ten miles, 

 the line A B 240 yards, and the diftance E C 3. quarter of a 

 mile, that the line D E will be fix yards, and the graduations on 

 it nine inches afunder, a fpace fufficient to prevent confufion or 

 miftake in afcertaining the place of the fignals fixed in the line 

 A B, or if at the point where the obferver is placed, a tclefcope 

 be fixed, with a micrometer annexed, it will be poffible to afcer- 

 tain the places of the fignals with a great degree of nicety, and 

 two lights in that cafe will be fufiicient to defignatc a word or 

 fentence. 



In order to effedl this an alteration muft be made in the vo- 

 cabulary, by changing the fymbols of the words, from letters 



to 



