Following the losses of British balloons to storms, the RFC attempted to get their own back on the Germans today with a concerted attack on 15 of the 23 enemy balloons in the hope of disrupting enemy observations during the preparations for the offensive.
Four balloons were shot down using Le Pieur rockets and one was destroyed by phosphorous bombs. One of the attackers, 2nd Lieutenant Beaufoi John Warwick Moore of 1 Squadron attacked in his Nieuport 16 (A116) and noted that the balloon went down in about 10 seconds after being hit by the rockets.
The rockets were invented by Lieutenant Yves Le Prieur of the French Navy and arrived at the front in April 1916. The rockets are a cardboard tube filled with 200 grams of black powder with a wooden conical head attached (by doped paper or linen tape) with a triangular knife blade inserted in a slot across its apex forming a spear point. A square wooden stick (usually pine) is taped to the rocket with about 5 feet extending back from the base of the rocket and fitted snugly into a launch tube attached to the aircraft interplane struts. The rockets are then fired electrically from the struts via a cockpit switch which launches all the rockets consecutively. The curved trajectory of the rocket means that the pilot must close to under 400 feet before firing them.
The first phosphorous bombs only arrived at the front on 16 June. They were invented by the RFC Experimental Section by Lieutenant Robert Benedict Bourdillon in co-operation with Captain Percy Henry Linthune and Major Bertram Hopkinson using converted phosphorus, the invention of Messrs. Allbright and Wilsons, of Birmingham.