Albert Ward (1917-2001[1]) stood in for William Hartnell as the First Doctor during the last three episodes of The Celestial Toymaker, as Hartnell was on holiday during the production of episodes two and three. Ward acted as a hand double, with the Doctor rendered mostly invisible by the Toymaker while he played the Trilogic Game. Pre-recordings of Hartnell's voice were heard during episodes two and four, "The Hall of Dolls" and "The Final Test" respectively. (DWM 196) Notably, the Doctor was made mute by the Toymaker for the entirety of the third episode "The Dancing Floor", making Ward the sole actor to portray the character during that episode.
Ward had earlier doubled for Hartnell's hand in The Romans in the scene where the Doctor burns Nero's plans (DWM 251) and would do so again in The Smugglers. (DWM 321)