How to Get to the North Pole Back in the 19th Century

Walking to the North Pole isn't as simple as pointing north and walking until you can't anymore. You have to undertake very, very careful and exacting navigation in order to make sure that you stay on course. The ice is moving constantly under your feet. It's pushing and pulling you in different directions. Back in the 19th century, there's no GPS. There's no sat nav, Google Maps, anything like that. So, actually reaching the North Pole back then wasn't as easy as it sounds.