Kika-evolution, 5, an Auguste clown, poses for a photo during Mexico’s 17th annual clown convention, La Feria de la Risa, in Mexico City, October 23, 2012. Approximately 500 clowns gathered at two local theaters in the capital city to exchange ideas, compete for laughs and show off their comedy performances. (Photo by Anita Baca/AP Photo)

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

Participants enjoy the “Color Me Run” festival in Hanoi, Vietnam, 28 May 2016. The festival which was inspired by the Holi Festival from India, attracted thousands of teenagers this year. (Photo by Luong Thai Linh/EPA)

A sacrificial camel gets a haircut with patterns at the animal market on the outskirts of Karachi, Pakistan September 22, 2015. Muslims across the world are preparing to celebrate the annual festival of Eid al-Adha or the Feast of the Sacrifice, which marks the end of the annual haj pilgrimage, by slaughtering goats, sheep, cows and camels in commemoration of the Prophet Abraham's readiness to sacrifice his son to show obedience to Allah. Eid al-Adha in India falls on September 25. (Photo by Akhtar Soomro/Reuters)

Revellers attend the Victorian Picnic during the Wave and Goth festival in Leipzig, Germany, May 22, 2015. The annual festival, known in Germany as Wave-Gotik Treffen (WGT), features over 100 bands and artists in venues all over the city playing Gothic rock and other styles of the dark wave music subculture. One of the biggest of its kind, the event attracts a regular audience of up to 20,000, the organisers said. (Photo by Hannibal Hanschke/Reuters)

A boy looks inside the skull of a Tyrannosaurus Rex replica at the Egidio Feruglio Museum in Trelew, Argentina, in this May 18, 2014 file photograph. Scientists on July 28, 2015 unveiled a comprehensive analysis of the teeth of the group of carnivorous dinosaurs called theropods, which include the Tyrannosaurus Rex, detailing a unique serrated structure that let them chomp efficiently through the flesh and bones of large prey. (Photo by Maxi Jonas/Reuters)

Clouds gather as walkers pause atop a ridge in Mountain View, California January 7, 2016. (Photo by Noah Berger/Reuters)

“After an afternoon of hiking and exploring the caves of Rhossili Bay, West Glamorgan, we caught the sun breaking through the clouds”. (Photo by Megan Warren-Davis/The Guardian)