In building simple mechanical models for his children from sheet metal, Hornby became frustrated that each model required parts that could be used to build that model only - each new model required a set of new parts, involving considerable labour. The inspiration and the means of achieving interchangeability, whereby parts could be assembled in different ways to produce different models, evidently occurred to Hornby during a train journey. The origin and history of the Meccano system, based initially on no more than 1/2"-wide strips of various lengths containing holes 1/2" apart, brackets, 8-gauge axles, wheels and nuts and bolts has been remarkably well documented, and research still continues.

Hornby was born in 1863, and by 1901 he was a book-keeper employed by David Elliott, a meat importer, whose premises were located in James Street in Liverpool, close to the seafront and the docks. The first patents for his novel system were granted in 1901, and the first set of Mechanics Made Easy went on sale later that year, comprising just 17 different parts (strips, brackets, axles, wheels, fixings, cord and nuts and bolts) and a leaflet showing the construction of 12 models - it sold for 7/6. The perforated strips were of tin plate, with folded edges, and square corners. Wheels were fully machined from brass, and a system of keys to couple the wheels to grooved axles was used. By 1902, bought-in parts were being packed in rented premises next door to Elliott's firm. For the first model-building competition advertised in 1903, the actual models were to be submitted for judging! An Accessories Box selling for 5/- contained the first gears - pinions, spur gears, contrates and worms. By 1905 five sets were available, each linked to the next by an Accessory Set, the number of different parts now totalling 38. The 121/2" Angle Girder appeared. In 1906 a starter Set X was added.