Sort:  

That is true, you can check out one of the links below to get the information on the earliest ones from Columbia university. They had lines that were external, with a tube that pushed a block that was connected to the car on rails - but they had problems with too much leakage.

The most successful were the internal ones, both above ground in tube and underground in tunnels. It really became a thing over in England for awhile. But I'll wager many people alive today didn't know about this one underneath the streets of NYC!

Coin Marketplace

STEEM 0.20
TRX 0.14
JST 0.030
BTC 66819.05
ETH 3320.89
USDT 1.00
SBD 2.75