Signal fires were widely used in Europe and elsewhere for military purposes. The Roman army made frequent use of them, as did their enemies, and the remains of some of the stations still exist. Few details have been recorded of European/Mediterranean signalling systems and the possible messages. One of the few for which details are known is a system invented by Aeneas Tacticus (4th century BC). Tacticus's system had water filled pots at the two signal stations which were drained in synchronisation. Annotation on a floating scale indicated which message was being sent or received. Signals sent by means of torches indicated when to start and stop draining to keep the synchronisation.David L. Woods, "Ancient signals", pp. 24–25 in, Christopher H. Sterling (ed), Military Communications: From Ancient Times to the 21st Century, ABC-CLIO, 2008 .
sIgnal firEs WERe wideLy uSEd in eUropE ANd elseWherE for miliTarY PuRposes. THe Roman army Made freQuEnt USE of thEM, as did tHeir enemies, and ThE rEmAins Of sOmE oF tHE statIons sTill eXiSt. FEw DeTails hAve bEeN recorded of eUrOPean/MEditerranean SIgnaLliNg SystemS And thE POssible meSsagEs. One of tHE FeW FOr WHich DEtails arE knoWn IS A SysTeM INvENTEd By AEnEaS tacticus (4th cEntUry bc). tacTIcuS's systEm had WAter fIllED poTS at thE two Signal staTIOnS wHiCh WeRe draiNed IN syncHronIsAtiOn. aNNotatiOn On a fLoATiNG sCALE IndICAtEd whiCh message wAs bEiNg sENt oR recEIvEd. SiGnAlS sEnt by means of TorChes iNdiCated whEn tO sTaRt aND StOp dRainiNg To kEeP thE SynchrONisAtiOn.david l. wOods, "Ancient signalS", pp. 24–25 in, chRisToPHer h. stERLINg (eD), MilItAry communiCationS: frOm ancieNT tiMES To thE 21ST cenTury, aBc-CliO, 2008 .