People stop to look at the thousands of so-called “love locks”, or “love padlocks”, that hang from a fence across the Hohenzollernbruecke bridge on September 13, 2011 in Cologne, Germany. Love locks are a growing phenomenon in cities across Europe and are meant by the couples who leave them behind as a symbol of their powerful and undying love for one another. (Photo by Dennis Grombkowski/Getty Images)

Egyptian bootblacks cleaning a European's shoes in Cairo. (Photo by Hulton Archive/Getty Images). Circa 1870

A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

A Mark IV tank, part of the parade at the Lord Mayor's Show in London. (Photo by Topical Press Agency/Getty Images). November 1917

A workman takes a siesta on a girder during the building of Radio City, the city of New York spread out below. (Photo by General Photographic Agency/Getty Images). Circa 1933

The Verreauxs Sifaka, otherwise known as Dancing Sifaka, who was caught strutting its stuff in Madagascar, has definitely learnt a lesson or two from King Julian – from the 2005 film “Madagascar”. Raising both of its arms and lunging from side to side, this lemur definitely likes to move it, move it. (Photo by Shannon Wild/Caters News Agency)

Look at the image for long enough and you can make the train change direction simply by thinking about it. Freaky.

“Today, we take photography for granted. Anyone can take a photograph simply by pressing a button. Yet, it was not always so simple. The invention of photography was announced in 1839, but during its first fifty years taking a photograph was a complicated and expensive business. In 1888, all this was to change following the appearance of a camera that was to revolutionize photography. Popular photography can properly be said to have started 120 years ago with the introduction of the Kodak”. – The UK National Media Museum. Photo: Two men on the deck of a ship, about 1890. (Photo by Collection of National Media Museum/Kodak Museum)