Some innovations give such an exponential productivity shift that they are often only appreciated when viewed with the perspective of history. Isambard Kingdom Brunel built the first train line from London to Bristol and cut down the travel times from days to hours. In doing so he actually moved time itself; at the time Bristol was 30 minutes behind London. Clocks in the 19th century were based off sunrise and sunset in each location as it was never necessary to be so precise when travel between two places meant a much longer journey. However the real benefit he provided was literally giving time to people, by shortening the travel time it enabled people to dedicate time to solving other problems. The spread of train tracks across the UK and the rest of the world enabled the rapid development of the Industrial Revolution that provided the foundation for the modern world. There is a fantastic documentary on Isambard Brunel on YouTube for those who wish to find out more.