part to the shop's location close to Edinburgh University. In 1853, Thin took a lease on two rooms above a shop at 54 South Bridge. The only access to these premises was by an external staircase from the street. Although these rooms were in the same block as the Infirmary Street shop, the only communication between them was by a speaking tube. Two years later the firm further expanded into an adjacent shop at 55 South Bridge (the premises previously occupied by Mr. Rickard). An opening was built into the back wall of this shop to give access to the Infirmary Street premises. Trade continued to improve and Thin was soon advertising the business as "the largest retail bookselling establishment in Edinburgh". James Thin worked in the business for the rest of his life. In 1880, he was joined by his eldest son, James Hay Thin, who became a senior partner. Overall, the firm remained in the family for five generations, ending with the founder's great-great-granddaughter, Jackie Thin, who served as managing director until the closure of the firm in 2002. During the second half of the 20th century, the firm grew into a national concern. It opened new shops and acquired existing ones throughout the UK, and also expanded into publishing. About half of its business came from educational markets. By the end of the century, it had 35 branches, with 650 staff and a stock of 85,000 titles. The South Bridge shop remained its flagship store and head office. In 2002, the company went into voluntary administration, having debts of £5 million. According to The Times, a significant factor in the firm's collapse was its rapid expansion into England in the mid-1990s. Church and public life In 1841, Thin joined the Bristo United Presbyterian Church (later Bristo United Free church) to which he was to devote considerable time and energy for the rest of his life. Having finished his apprenticeship that year, he started teaching religious instruction in evening classes at the church's mission in Cowan's Close. He continued in that role for eleven years, during which time attendance at the classes rose from 30 to 140. He then took charge of the senior female class at the Christian Instruction Society, which met at the Old Session House in Bristo. This work lasted until 1861, after which he became a teacher at the society's young men's classes. In