The book “Elektroschutz in 132 Bildern” (Electrical Protection in 132 Pictures) was published in Vienna in the early 1900s by a Viennese physician named Stefan Jellinek (1878-1968, a founder of the Electro-Pathological Museum). The pictures are nice and direct and unambiguous; they teach, graphically, that the surest way to kill yourself with electricity is to form a complete path from source (usually the bright red arrow) to ground (the screened back, pink arrow). Arrowheads provide the path for current flow. (Photo by The Vienna Technical Museum)

Pfc. Sebastian Rodriguez, machine gunner, Weapons Platoon, Lima Company, 3rd Battalion, 3rd Marine Regiment, Marine Rotational Force – Darwin, fires an M240 machine gun during a night squad-attack exercise, here, May 22, 2013. (Photo by Sgt. Sarah Fiocco/U.S. Marines)

Actors perform a scene in a film directed by Humam Husari in the rebel-held besieged town of Zamalka, in the Damascus suburbs, Syria September 19, 2016. (Photo by Bassam Khabieh/Reuters)

English fashion modelDaisy Lowe performs a DJ set for Badoos #DateOfTheDead party at La Bodega Negra on October 26, 2017 in London, England. (Photo by Tabatha Fireman/Tabatha Fireman/Getty Images for Badoo)

A motorcycle carrying protesters holding a placard using the acronym of the national electoral commission, drives ahead of demonstrators on foot calling for the disbandment of the commission over allegations of bias and corruption, in downtown Nairobi, Kenya Monday, June 6, 2016. (Photo by Ben Curtis/AP Photo)

Sara White, dressed as Ginny Weasley, a fictional character in J. K. Rowling's Harry Potter series, poses for portrait at the launch of “Harry Potter and the Cursed Child” at Foyles book store on July 30, 2016 in London, England. The script book of the play of the same name, which is on at Palace Theatre, billed as the eighth Harry Potter story, is on sale from midnight tonight. (Photo by Rob Stothard/Getty Images)

Russia's Darya Klishina prepares for the women's long jump qualification during the athletics competitions of the 2016 Summer Olympics at the Olympic stadium in Rio de Janeiro, Brazil, Tuesday, August 16, 2016. She might be feeling the pressure of being all alone, but Darya Klishina could yet still win Russia's only athletics medal at the Rio 2016 Games. (Photo by Matt Dunham/AP Photo)

In this Monday, January 30, 2017 photo, wildfires straddle Chile's Dichato community. Strong winds are continuing to stoke the flames of raging wildfires in Chile, forcing the evacuation of more than 800 families in the coastal town of Dichato. (Photo by Esteban Felix/AP Photo)