One of the simplest calculations we have used in this series is multiplying 4 by 5 and we again use it for a couple of the motors used on the Snaefell Mountain Railway. Although both were originally built in 1895, 5 was rebuilt in 1971 although to the casual observer you won’t notice much difference. We are at Laxey on 16th August 2013 for this photo of the two which were working up and down to the summit as they have done many times over the years. (Photograph by Gareth Prior)