Sir, – Further to recent correspondence (April 5th), the nautical mile is the maritime, aviation and satnav gold standard for measuring distances on the globe as it is the angle from the equator to the pole divided into 90 degrees, each degree being 60 nautical miles, and each second of arc being exactly one nautical mile.
Land-based units like the “mile” (one thousand paces of a Roman soldier) or the “kilometre” (a ten-thousandth of the distance from the equator to the pole) were simply convenient conventions, the latter being inspired by the French revolutionaries’ desire to annoy the English and was based on our having 10 fingers. They also wanted 10 days in the week, etc.
Had human beings only three fingers on each hand, the mile and the kilometre would be almost the same! – Yours, etc,
GEORGE REYNOLDS,
Blessington,
Co Wicklow.