The Wrist Knot
Stretch the handkerchief between the finger and thumb in both hands, as in [Fig. 3]. Cast a loop towards the left hand, taking care that it is thrown outwards. As the loop is made, the left hand, still with the end of the handkerchief between finger and thumb, is passed smartly through the loop from the outside—shown by the dotted lines in the illustration.
This loop is now loosely round the left wrist, and the knot can be made taut by pulling the ends with both hands. The instant it is drawn tight let go of the ends of the handkerchief, and the result will be that a simple twitch of the right hand has seemed to tie a knot firmly round your left wrist.