Disconcert caused to the technicians, sent by the municipality to fix a water leak on the roof of the "Manzoni" school in Vestenanova (Verona), when they found it being caused by a gas-tank cap (about 15 cm wide) fallen somewhen from an airplane. The only information for the investigators are the engravings on the cap, indicating the place of production (American Shaw Aero Devices) and the code registration...