BLAIR of Athol, a castle belonging to the duke of Athol, seated in the county of Athol in Scotland, 28 miles north-west of Perth. W. Long. 3° 30'. N. Lat. 56° 46'. This castle was besieged by the Highland army in 1746; and bravely defended by Sir Andrew Agnew, who was reduced to eat horse's flesh, until he was relieved by the Hessians under the earl of Crawford.