With thread and adhesive tape you made a cross, as in Fig. The cross will be centred in the central star of Orion belt. This is to maintain the zone fixed while observing and counting. It has to be possible to see Orion from those points, and have to be above all public lights. The observers have to be in place at least 15 minutes before the accorded time, to become used to obscurity.
All observers count the visible stars inside the tube.
They hold the tube in front of an eye, the other one being softly covered with the extended hand, as shown in Fig. Then, they change eyes. Then, they wait for 5 minutes and repeat the whole procedure for three times.