For interest, an American self-promoter, racing driver, and showman called Barney Oldfield, immediately after setting the world land speed record at 131 mph in 1909, said he had travelled "As near to the absolute limit of speed as humanity will ever travel." He followed this with a line of showman-tripe about how his vision was fading in and out and he was experiencing respiratory problems, while travelling at that speed.
You may get the idea from this of my opinion of the line that mowers, or anything else, have been "pretty well perfected".
