Coryat's Crudities: Dave Ball Experiment Dave's experiment was to push along a scale model of a National Express coach at what appeared to be a realistic-looking average speed (i.e. if the model was 72 times smaller than a full-sized coach, then it would be driven 72 times slower than, say, 60mph). The model was to be pushed around the entire perimeter of Nottingham’s Old Market Square (apparently one of the largest urban open spaces in Britain and currently closed to the public for renovation work), with the time taken being recorded. Using this figure, and that of the estimated average speed of travel, the total distance covered could then be calculated – thus providing a highly inaccurate and subjective measurement of the perimeter of the square. Findings The coach was pushed around the entire circuit - without stopping - in a time of 13 minutes 57 seconds (or 837 seconds). Given that the scale of the model was 1:76, and the avarage speed was judged by the artist to be the scaled-down equivalent of 80km/h, the true speed would thus be 1.053km/h (or 0.29 metres per second). So, knowing that distance is equal to speed multiplied by time (837 x 0.29), the perimeter of the Old Market Square can therefore be calculated to be 244m.