The luckless girl to birched would have been kept under lock and key while waiting for her birching. She may have been secured by ankles wrists and waist in a bent-over position on a purpose made “birching stool” A birching stool was a piece of apparatus that may built by a local carpenter or in the school itself. It made the process of birching more efficient as the culprit was held in a fixed position unable to move with her bottom presented in an optimum position for the attention of the birch-rod.
Any clothing, drawers, knickers etc would be cleared from the area to be dealt with and then the birching would be administered to the girl’s bare backside by an appointed mistress. A birching may have been up to 12 strokes. This would either be in private or maybe in front of the school if it was meant to serve as warning to others.