James Watt and the Steam Engine by H.W. Dickinson and R. Jenkins is a book, which has proven to be a very valuable source for me since many years. First published in 1927 it contains a wealth of information. The authors have dealt with all the first level sources, i.e. letters, notebooks, drawings etc. One of the book’s tables shows a “Portable Rotative Engine, 10 inch Cylinder, for Reynold’s & Co”. This is a very early whim engine. I decided 2018 to build a model of this engine to have an attractive model of a Watt engine in August 2019 - the bicentenary of his death.
Dickinson calls the Reynold’s Whim Engine an “exceptional construction”. This is somewhat reluctant because it is a beam engine on a truck. From the early mining in my home area (the Ruhr) I know that shafts were sometimes only rather small distances apart from each other. If mining at one spot turned out to be sparse, a new shaft was digged some hundred meters away. I presume this has been practice in England too. The Reynold’s Whim Engine could be relocated by means of e.g. horses to the new place, the winding drum was fixed and both parts were arranged so that the gears meshed nicely. Dickinson states, that the boiler was “a fixed construction”. Messrs. Reynold’s must have seen advantages compared with the standard “horse whim”, because they ordered two of these engines from Boulton & Watt.
Some of the main dimension are known. Wheel base was 10 ft, about 3 m, Cylinder 10 in, stroke 3 ft, that is a bore of approx. 250 mm and stroke 940 mm. Flywheel 10 ft, about 3 m. The model’s scale is 1:15. It is powered by compressed air.
On my YouTube-channel is a video of my model.