On we go past New Bridge, which is one of the oldest, if not the very oldest, of the many bridges which cross the River. Close at hand the Windrush joins forces, and the River swells and grows wider as it sweeps off to the north. Away on the hill on the Berkshire side is a little village known as Cumnor, which is not of any importance in itself, but which is interesting because there once stood the famous Cumnor Hall, where the beautiful Amy Robsart met with her untimely death, as possibly some of you have read in Sir Walter Scott’s novel “Kenilworth.” Receiving the Evenlode, the River bends south again, and a little later we pass Godstow Lock, not far from which are the ruins of Godstow Nunnery, where Fair Rosamund lived and was afterwards buried. Between Godstow and Oxford is a huge, flat piece of meadowland, known as Port Meadow: this during the War formed one of our most important flying-grounds. Henceforward the upper Thames is interrupted at fairly frequent intervals by those man-made contrivances known as _locks_—ingenious affairs which in recent years have taken the place of or rather supplemented the old-fashioned weirs. For any river which boasts of serious water traffic the chief difficulty, especially in summer-time, has always been that of holding back sufficient water to enable the boats to keep afloat. Naturally with a sloping bed the water runs rapidly seawards, and if the supply is not plentiful the river soon tends to become shallow or even dry. In very early days man noticed this, and, copying the beaver, he erected dams or weirs to hold back the water, and keep it at a reasonable depth. And down through the centuries until comparatively recent years these dams or weirs sufficed. As man progressed he fashioned his weirs with a number of “paddles” which lifted up and down to allow a boat to pass through. When the craft was moving downstream just one or two paddles were raised, and the boat shot through the narrow opening on the crest of the rapids thus formed; but when the boat was making its way upstream more paddles were raised so that the rush of water was not so great, and the boat was with difficulty hauled through the opening in face of the strong current. This very picturesque but primitive method lasted until comparatively recent years. Now the old paddle-locks have gone the way of all ancient and delightful things, and in their places we have the thoroughly effective “pound-locks”—affairs with double gates and a pool or dock in between—which in reality convert the river into a long series of water-terraces or steps, dropping lower and lower the nearer we approach the mouth. CHAPTER TWO _Oxford_ One hundred and twelve miles above London Bridge there is the second most celebrated city on the banks of the Thames—Oxford, the “city of spires,” as it has been called. By no means a big place, it is famous as the home of our oldest University.