The British publishing firm of Nelson began as a small bookselling business established in Edinburgh in 1789. The founder of the bookshop was Thomas Neilson (1780-1861). Neilson extended his interests to include publishing, beginning with the publication, in monthly parts, of Bunyan’s 'The Pilgrim's Progress'. In 1818, the name of the firm was changed to Thomas Nelson because of the tendency among customers to misspell Neilson. In 1835, Thomas was joined in the business by his son William and a little later by his younger son Thomas. The business, located in Edinburgh's West Bow, grew on the formula of reprinting standard authors at low prices, and opened branches in London and New York. In 1858 the name of the firm changed to Thomas Nelson and Sons. In Edinburgh during 1845-46, the firm moved to larger custom-built premises at Hope Park just to the south of the city centre. There, with a workforce of 600, all the activities connected with the production of books were carried out under one roof: printing, stereotyping, bookbinding, lithographing, engraving, woodcutting, warehousing, and even dyeing of the plain white calico used in bindings. From 1856, colour-printing became a feature of their production and by 1860 the firm was the leading publisher of cheap colour-printed titles. From his earliest years with the firm, Thomas exhibited a mechanical bent and in 1850 he invented a rotary press with curved stereotyped plates fixed on cylinders and with a continuous web of paper - the type of press used in the newspaper industry well into the 20th century. Nelson’s production focused on story books, religious books and books of travel and adventure by popular authors, particularly intended for young readers. A series of school books was initiated, and after the Education Act of 1871, which had prompted a demand for improved school-books, Nelson's began their series of Royal readers. John Buchan (1875-1940), writer of fiction and history, was a literary adviser and the firm also published his work. Other authors published include Bagehot, Belloc, G.K.Chesterton, Erskine Childers, H. J. Newbolt, Mark Twain and H.G. Wells.