Devant was a pioneer of early cinema in London. On 19 March 1896 Devant showed the first films ever seen in the UK. These Edison films were shown at Maskelyne’s Egyptian Hall using a film projector (known as the Theatrograph) made by R.W. Paul, two days before Paul himself demonstrated his new machine in public at Olympia. Also that year Devant began his association with the pioneer of cinematic special effects, Georges Méliès, to whom he sold a Theatrograph. Devant then toured the country showing films, and for a time became Méliès’ sole agent in Great Britain selling both his films and cameras. As well as being an early exhibitor of film, Devant appeared in three films made by Paul and another by Méliès ("D. Devant, prestidigitation", 1897). Méliès also used one of Devant’s stage acts, which involved making a portrait of a woman come to life, to create his 1903 film, "The Spiritualist Photographer" ("Le Portrait Spirite").