Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925

Members of Japanese idol group Kamen Joshi (Masked Girls) pose for a photo after a rehearsal for a concert at their theatre in Tokyo's Akihabara district, Japan March 17, 2016. For countless girl and pop-idol bands in Japan, standing out from the crowd can be daunting, but one group – “Kamen Joshi” – seems to have found the answer by hiding behind masks. The Tokyo-based all female band has 18 members, split into three groups that perform across Japan and elsewhere in Asia. (Photo by Toru Hanai/Reuters)

A man dressed as a devil poses next to a grafitti of late rebel hero Ernesto "Che" Guevara in the indigenous community of Monimbo in Masaya, Nicaragua, October 16, 2015. People prepare to participate in the popular annual festival called "The Aguizotes" held on the last Friday of October, where residents dress up as characters from legends and folklore mythology of Nicaragua. (Photo by Oswaldo Rivas/Reuters)

A boy performs a masked dance as he participates in a parade during the National Encounter of Mask festival in Barva de Heredia October 30, 2015. (Photo by Juan Carlos Ulate/Reuters)

Irene Aguirre, 23, attends a boxing class at the National Institute of Sport in Managua March 4, 2015. A study done by the Psychology alumni of the National Autonomous University of Nicaragua (UNAN-Managua) revealed that about 1 million women in Nicaragua suffer from domestic violence. (Photo by Oswaldo Rivas/Reuters)

“A ball girl is an individual who retrieves balls for players or officials in a variety of sports including association football, American football, tennis, baseball and basketball”. – Wikipedia

Photo: A ball girl runs with 2 balls for Ivo Karlovic of Croatia against Fernando Verdasco of Spain in their second round match during the Mutua Madrilena Madrid Open tennis tournament at the Caja Magica on on May 11, 2010 in Madrid, Spain. (Photo by Clive Brunskill/Getty Images)

Natsumi Hayashi is a Japanese artist known for her fixation with levitating. Two years, ago, the photographer began posting portraits online of herself floating in mid-air. The magical project – titled “Today's Levitation” – is the subject of a playful survey of her year-long obsession with flying.