Instructions: Pour water into the ashtray until the water is ~1cm deep. Push three matchsticks into the slice of lemon, in the shape of a triangular pyramid, with the match heads together at the top point of the pyramid.
Place the lemon and matchsticks in the centre of the ashtray, so that they float on the water. Light the fourth match and use it to light the other three together. Invert the pint glass over the lemon and matches, letting it sit inside the ashtray or frisbee! Watch as the lemon slice magically levitates within the pint glass!