John Joseph Merlin he wheeled about himself, with great facility to any part of the room." At an event held by Teresa Cornelys in Carlisle House, Soho Square, Merlin appeared somewhat disastrously on roller skates of his own invention. By April 1783 Merlin was putting his musical instruments and his automatons on display at his own museum. Advertisements invited readers to visit his Museum of Musical Instruments and Mechanical Inventions at No. 2, Princes Street, Hanover Square, London. Well-off Londoners could meet their friends at Merlin's Mechanical Museum in the afternoon or evening, pay to see the exhibits, and drink tea or coffee
John Joseph Merlin remarried at least once, to Marie Therese Dechesalle in 1743, and had another child, Charles Merlin. The family moved several times. From ages 19 to 25, Merlin lived in Paris, where he was involved in the Paris Academy of Sciences. Merlin arrived in England on May 24, 1760, as a technical advisor to the new Spanish Ambassador to London, Juan Joaquín Anastasio Pignatelli de Aragón y Moncayo, conde de Fuentes (15th). As of 1763, Jérôme Lalande recorded that Merlin had helped to complete a large barrel organ which was built for the Princess of Wales. By 1766, Merlin was working