Physics of impact aside for the moment, M.Carron’s bullet capsule would be released from the top of the interior of the Tower, about 1000 feet high, and released to fall into an excavated pool 150’ across and 200’ deep. The idea was that in addition to the springs inside the capsule, the water would act as a “shock absorber”, and so “the shock felt by the occupants on landing will be in no way unpleasant”.Dreaming of the 10-Ton Eiffel Tower Bullet, 1891
[Okay, so the thing would hit at 178mph or so, and, assuming that the whole thing didn’t get completely crushed on impact, I’m not so sure that 200’ of depth is very much wiggle room for the thing to come to a halt (if it didn’t deform). Also it would have to not have any wind deflection so as to not veer off its perfect entry into the water. And so on. Calculating the force of impact is difficult without knowing how far down the bullet would go, but hitting the water at 80 m/s and stopping at 30 meters would yield something like 28,600,000 KE and 1,274,000 N. There are lots of problems…]
The thing is, though, the thing that made this so appealing, is that for the 20-francs that get a person a seat in the bullet, that they would each get to go twice as fast as any human had ever traveled before ( 65 miles per hour was about the speed of the fastest train constructed).