the quivering motion of the air on a hot day, a heat-haze. Cowt means colt and there is a similar English dialect phrase “the summer colt rides” for the same phenomenon. In Scots, simmer-cowts usually appear in the plural: The blistering “simmer coutts,” as we used to call the earth-shimmer (Scots Magazine July 1943). As these atoms of the sun (which we commonly call summer colts) do in a sun shine day before or after rain in the heat of summer (J. Howie An Alarm unto a Secure Generation 1780).