Aeronautics - Aerial Machines from the book New Popular Educator (1904), a vintage collection of early aerial machines.… Free Image from public domain license 
Electric-Eel (Gymnotus Electricus) from Ichtylogie, ou Histoire naturelle: génerale et particuliére des… Free Image from public domain license 
Electric Ray (Raja Torpedo) illustration from The Natural History of British Fishes (1802) by Edward Donovan (1768-1837).… Free Image from public domain license