River Lune painted by J. M. W. Turner. The M6 motorway crosses the Lune near Tebay and Halton-on-Lune; in 2015 it was joined by the Heysham to M6 Link Road. The Ingleton branch line, a railway operational between 1861 and 1967, followed the Lue between Tebay and Kirkby Lonsdale, crossing the river twice on viaducts which still stand. Near the end of the non-tidal reach of the river stands the Lune Aqueduct, which carries the Lancaster Canal. The Lune is now tidal only below Skerton Weir in Lancaster. Four bridges in close proximity cross the estuary in Lancaster: Skerton Bridge (road), Greyhound
Lune of Hippocrates circle. He proved that the lune bounded by the arcs labeled "E" and "F" in the figure has the same area as triangle "ABO". This afforded some hope of solving the circle-squaring problem, since the lune is bounded only by arcs of circles. Heath concludes that, in proving his result, Hippocrates was also the first to prove that the area of a circle is proportional to the square of its diameter. Hippocrates' book on geometry in which this result appears, "Elements", has been lost, but may have formed the model for Euclid's "Elements". Hippocrates' proof was preserved through the "History