In days when the bale-fire's red glare on the sky by night, or its heavy column of smoke by day, was the only means of warning the country of coming invasion from the south, Home Castle, with its wide outlook, was the ideal centre of a system of beacon signals on the Scottish border. The position was matchless for such purpose; nothing could escape the watchful eyes of those perched on the lofty battlements of this "Sentinel of the Merse," no flaming signal from the fords over {024}Tweed fail to be seen. In an instant, at need, fires would be flashing their messages over all the land, warning not only the whole Border, but Dunbar, Haddington, Edinburgh, and even the distant shores of life. "A baile is warnyng of ther cumyng quhat power whatever thai be of. Twa bailes togedder at anis thai cumyng in deide. Four balis, ilk ane besyde uther and all at anys as four candills, sal be suthfast knawlege that thai ar of gret power and menys." So ran part of the instructions issued in the fifteenth century. But almost in our own day--at least in the days of the grandfathers of some now living--Home Castle flashed its warning and set half Scotland flying to arms. Britain then lived under the lively apprehension of a French invasion. With an immense army, fully equipped, Napoleon lay at Boulogne waiting a favourable opportunity to embark. Little wonder, therefore, that men were uneasy in their minds, and that ere they turned in to bed of a night country folk cast anxious glances towards some commanding "Law" or Fell, where they knew that a beacon lay ready to be fired by those who kept watch. In the dull blackness of the night of 31st January, 1804, the long-looked-for summons came. All over the Border, on hill after hill where of old those dreaded warnings had been wont to flash, a tiny spark was seen, then a long tongue of flame leaping skyward. The French were coming in earnest at last!