Legend has it that Spooner was an early supporter of the metric system, purportedly being a secret sympathizer of Napoleon . He thus aimed for a gauge of 600 mm, but due to discrepancies in the way the gauge was measured, it ended up being 3mm short by the modern method of measurement (1' 11" working out at 597mm, 2' being 610 mm). If true, this would make it the world's first railroad to use a metrically defined gauge (besides a long list of other firsts that the Ffestiniog can claim). Other sources, however, suggest this is probably just an urban legend. One might observe, for example, that the dates don't align.