club track gauges are 3½", 5" and 7¼", and 4¾" and 7½" in North America. Larger miniature railway gauges such as 10¼" and 15" gauge are more common in zoo and park settings or as public passenger-hauling lines such as the Romney, Hythe & Dymchurch Railway. Various gauges have existed over time. 3½" and 5" gauge were proposed in 1898 as standard model gauges, although 5" gauge only became popular after the Second World War, along with 7¼" gauge. Not all model live steam locomotive enthusiasts are model engineers (and vice versa). There are many live steam enthusiasts who prefer running the models on a track rather than spending long hours building them in a workshop, and so purchase a ready made model locomotive. However, for many the joy of the hobby lies in the manufacturing process, ending in the great satisfaction of a running engine of any sort, which can be immense. Model engineering in society The aim of model engineering to build mechanical models is now usually purely recreational, although beginning with the industrial revolution in the late 18th century through to the late 20th century such models were widely produced as aids to technical education, either as apprentice projects or as classroom or public institutional exhibits. They were also produced as commercial props to support a patent, to visualise a proposed capital venture, or to advertise a manufacturer's trade. Many museums in the old industrialised countries house original collections of mechanical models stemming from the earliest days of the industrial revolution. One of the earliest known models of a steam engine, that of a Newcomen beam engine, was made prior to 1763. The Science Museum, London published catalogues illustrating many early models. Many of these models represent the same subjects that remain popular with model engineers today, which attests to the long tradition of model engineering. The earliest publication to offer instruction to the public on building working steam engine models was the Model Dockyard Handy-book (2nd edition 1867) by E. Bell, proprietor of the Model Dockyard shop in London, which also offered the parts and completed models for sale. Bell was, he said, "Ship Modeller and Mechanist" to the Royal Family, the English Admiralty and various European royalty. The book was aimed at building and operating these models as a recreational pursuit. In Britain, the establishment of a broad middle class by the late nineteenth century,