 In 1878 or 1879 he built his own version of Edison's sound recording device, the Phonograph, and recorded himself calling out the hours for an Experimental Talking Clock he was developing for the Ansonia Clock Company in Connecticut.However, the attempts to make a commercially viable "phonograph clock" proved unsuccessful.After being restored by Aaron Cramer, Lambert's talking clock is currently at the National Watch and Clock Museum in Columbia, PA, and is listed in "The Guinness Book of World Records" and in "The Encyclopedia of Recorded Sound" as the world's oldest playable recording.