I originally said that this was "the Site of Ridges Weir, otherwise Langleys, Cocks, Rudges, Butlers."
However Julie Godson in her book "The Water Gypsy" has identified Noah's Ark Island and weir, below Northmoor Lock as the Rudge's weir in her story and so I have moved the details I have to that page
1860: Ridges Weir, Henry Taunt -
Ridges Weir, Henry Taunt, 1860
© Oxfordshire County Council Photographic Archive; HT1149
1879: Harts Footbridge built.
1880: Harts Weir removed.
1909: The Stripling Thames, Fred Thacker -
Above [Northmoor] lock is Ridge's footbridge, over the site of another dismantled weir; Ridge's or Langley or Cock's. From the crown of this bridge, which lies at the exact point at which the River ascends northward for its long sweep round by Oxford and southward again to Abingdon, you may behold a true vision of the soul of remote Thames landscape. Across the Oxfordshire meadows lie the grey roofs and barns of tiny Moorton; and hence if you choose, is the nearest way from the River to Fyfield; across Appleton Lower Common, desolate under a bleak August sky the day I was there, then over a little ridge and through the hamlet of Netherton.
Harts (Ridges) Footbridge in 1910.
1920: Fred Thacker -
It is now a very picturesque scene. Close by, on the Left bank,
[just discernible in the 1910 photograph above, between the willows and the tall reeds]
is an ancient thatched house of some size, which may have been the weir keeper's. The bridge crosses at the exact point at which the river ascends northwards for its long sweep round by Oxford and thence southward to Abingdon: only six miles away as the crow flies, although some twenty-four by water.
Hart's Footbridge in 1999.