Engineering drawing photographed by Jack Davies from L. T. Catchpole’s The Lynton & Barnstaple Railway. Preserved among Jack’s own negatives, it was evidently retained as reference material for the Manning Wardle locomotive he subsequently built.
The drawing also illustrates something of the skill involved in Jack’s work. He was not simply assembling a model from a commercially supplied kit or following a ready-made set of model-engineering plans. Starting with information about the full-sized locomotive, he had to translate the original design into a much smaller working steam engine.
That involved considerably more than reducing every measurement by the same proportion. The dimensions and appearance of the prototype had to be preserved while the boiler, cylinders, valve gear, bearings, steam passages and other working components had to function successfully at miniature scale.
Among Jack’s surviving negatives are a number of photographs of drawings, diagrams and magazine articles. They suggest that his photographic collection also served another purpose: it was, in part, his own engineering reference library.