...then again, his Atmospheric Railway was a glorious expensive failure. An evacuated tube carried a piston pushed by the atmospheric pressure behind it (hence the name). The piston had a connecting rod to attach a carriage. Quiet, clean, lovely.

Pumping houses along the route made vacuum for each leg. It was a great idea, but materials science wasn't up to it: the seals kept cracking in the sea air and rats ate the leather skirt that kept vacuum round the piston rod. It was out of service a lot, and was soon abandoned for traditional railway.

I don't want Musk's implementation of a spitball idea that's been going round for ages to be like that, but I can't help wondering...