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 which the arc "AEB" lies. Consequently, the smaller circle has half the area of the larger circle, and therefore the quarter circle AFBOA is equal in area to the semicircle AEBDA. Subtracting the crescent-shaped area AFBDA from the quarter circle gives triangle ABO and subtracting the same crescent from the semicircle gives the lune. Since the triangle and lune are both formed by subtracting equal areas from equal area, they are themselves equal in area. Using a similar proof to the one above, Alhazen showed that two lunes, formed on the two sides of a right triangle, whose outer boundaries