A three wheeled “cabin” scooter manufactured by German aircraft engineers Messerschmitt & Co at factories in Regensburg. (Photo by Hans Enzwieser/BIPs/Getty Images). 1955

A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

A model of a ghost made from translucent fibreglass is lit from inside at Gem's (Wax Models) Ltd, in the Portobello Road area of west London. The ghost is due to go to the Capistrano Mission Museum in California, where tourists are told the legend of how he frightened a young Indian girl novice to death. 1st May 1965. (Photo by Chris Ware/Keystone Features)

Clouds float over an open field January 3, 2007 in Shirley Heights, Antigua. (Photo by Joe Raedle/Getty Images)

Father Christmas arriving at the Arding and Hobbs store in Clapham Junction, London, 2nd November 1926. (Photo by H. F. Davis/Topical Press Agency/Getty Images)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

A Chinese People's Liberation Army soldier marches with members of an honor guard as they prepare for a welcome ceremony for visiting Luxembourg's Prime Minister Xavier Bettel outside the Great Hall of the People in Beijing, Monday, June 12, 2017. (Photo by Andy Wong/AP Photo)