TO PREDICT THE HOUR YOUR FRIEND INTENDS TO RISE ON THE FOLLOWING MORNING
Request your friend to make up his mind as to the time he intends to rise on the following morning, and then to mention an entirely different hour to you. To the latter you mentally add twelve, and giving him the number of the total, request him to look at his watch, and starting at the hour preceding the one he has selected for rising, to count backwards until he reaches the number you have given him, beginning with the number which he previously gave you. Ask him to state the hour at which he stops, which he will find is the one he selected for rising. For instance; supposing your friend intends to rise at nine and gives you 58 four. To four you mentally add twelve and request him to start at the hour before his getting-up time (which would be eight) and count sixteen backwards on the face of the watch, starting with the number he gave you—four—and when he reaches sixteen his finger or pencil will rest upon nine, the hour he selected for getting up.