Donald Walker, Walker's manly exercises (1855)
“ To shorten the curb rein, and lengthen the snaffle, we take in the right hand the centre of the curb rein, that hangs over the fore-finger, slip the whole of the reins too long, pass the left hand down them, and feel with the fingers whether both the curb reins are of equal length, before we grasp with the left hand, or quit with the right. ”
