He was stumped by the valve of the pump.
Actually, there was another issue: how was the piston of the pump made? Is there no gap between it and the cylinder? Won't it leak while pumping?
Inside the piston is a metal block, machined on a lathe, and the gap with the cylinder is very small. A rubber sheet was made for it, and oil was added, which also helps reduce the gap.
If the shape of the pump valve and the tire valve match, will it not leak when connected?
He didn't know.
His experiment showed it leaked.
Even when a rubber pad was placed at the bottom of one side of the tube and pressed firmly, it still leaked.
He thought the main reason was that the shape of the tube he made was not standard enough.
He could process medium-sized tubes to standard, but larger tubes couldn't be processed to standard.
His hope was this:
A large tube covering a smaller tube, with almost no gap in between.
A larger tube covering this relatively large tube, also with almost no gap in between.
