Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

Two sailors from HMS Fury enjoy a smoke with two women in bathing suits on a beach in Jersey, where their ship is on a visit. (Photo by William Vanderson/Fox Photos/Getty Images). 29th June 1935

Judy, a black collie whose owner was killed by a train when trying to retrieve her after she slipped her lead. (Photo by Evening Standard/Getty Images). 17th December 1976

A soldier poses with a Hythe Mk III Gun Camera during training activities at Ellington Field, Houston, Texas in April of 1918. The Mk III, built to match the size, handling, and weight of a Lewis Gun, was used to train aerial gunners, recording a photograph when the trigger was pulled, for later review, when an instructor could coach trainees on better aiming strategies. (Photo by Harry Kidd/WWI Army Signal Corps Photograph Collection via The Atlantic)

Three Chinese soldiers at the time of a civil war in China. (Photo by General Photographic Agency/Getty Images). 1922

People participate in the first day of Thingyan Water Festival in Naypyitaw, Myanmar on April 13, 2018. The annual water festival, known as Thingyan, features large groups of people congregating to celebrate the by splashing water and throwing powder at each other's faces as a symbol of cleansing and washing away the sins from the old year. It marks the start of the traditional New Year and is similarly celebrated in countries such as Myanmar, Thailand, Laos and Cambodia. (Photo by Hein Htet/EPA/EFE/Rex Features/Shutterstock)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)