The Supermarine P.B.31 Night Hawk with searchlight in nose and Davis gun mounted on the Scarff ring on the top wing.

The 60ft-span Night Hawk minus its armament. a “Battleplane” armed with three COW guns as well as machine-guns.

The Royal Aircraft Factory N.E.1, or Night-flying Experimental, was designed in 1917 and was powered by a 200 h.p. Hispano-Suiza engine. Armament consisted of either a COW quick-firing gun or a Vickers “rocket gun”.

The Fairey N.4 variant N129 Titania was, in its day, the largest flying-boat in the world. It had a span of 140ft and a gross weight of more than 30,000lb. There were apparently plans to equip N129 with a COW gun - can anyone confirm this?

Two artists’ impressions of the COW gun mounted flexibly in the nose of the Westland Westbury.

The Vickers F.B.25 two-seat night fighter of 1917, fitted with the Crayford “rocket gun” for use against Zeppelins.