The amount of river gravel left in the part of the Thames Valley on which West London is built is extraordinary. It is all round, and mostly red, and as there are no rocks like the stone which makes up most of this gravel anywhere in the modern valley, it is puzzling to know where it came from. I went to see the digging of the foundations of the new South Kensington Museum, and the great excavation, which was like the ditch of a fortress, and the stuff thrown out, which was like the rampart, was all dug in, or made of, river gravel.