Another bright but cold and blustery day. I returned to the Thames. This time I walked the other way, toward Tilehurst and away from London. Racing boats with four and eight rowers followed me all the way. When the first boat passed by, I noticed a new design of the oars. They were asymmetrical: the lower part of the paddle, which dipped into the water first, was considerably wider than the upper part. Then I noticed the same thing on the next boat. And the next. At length, since the last time I walked along this section of the Thames some seven or eight years ago, the spread of the innovation in the design of the oars had not only begun but also ended.