The mass-produced wooden clocks manufactured from interchangeable parts that poured from Terry's factory beginning in 1814 were the world's first mass-produced machines made of interchangeable parts. As such he would mass market an affordable, complete cased-clock to American consumers. Terry's first clocks were offered in plain wooden box cases. Terry is also credited with the design of the pillar and scroll case. In his autobiography, "History of the American Clock Business for the Past Sixty Years and Life of Chauncey Jerome," Terry's employee and assistant Chauncey Jerome, later a great clockmaker and owner of the world's largest clock factory, mentions building the first pillar and scroll in Terry's workshop with the master's design and under his direction. The pillar and scroll case provided a large, clear dial in a wooden case about thirty inches tall and six inches deep. The upper part was the clock face, the lower part was either a mirror or a picture back-painted on glass. Despite the small size of the clocks compared with traditional long case clocks, Terry was able to provide sufficient power through gearing for the clock to run a full thirty hours before it needed to be rewound. Anticipating a successful product Terry had the foresight to patent his arrangement of clockworks. At least five patents were issued to him through the years up to 1825 in order to protect his invention.