Latest By
Category:


Armor
Artificial Intelligence
Biology
Clothing
Communication
Computers
Culture
Data Storage
Displays
Engineering
Entertainment
Food
Input Devices
Lifestyle
Living Space
Manufacturing
Material
Media
Medical
Miscellaneous
Robotics
Security
Space Tech
Spacecraft
Surveillance
Transportation
Travel
Vehicle
Virtual Person
Warfare
Weapon
Work

"No one has ever produced a statement of fact that was technically true. The most accurate statements of science we have today are accurate to only 15 decimal places."
- Bart Kosko

Electrified Fence  
  A wire fence carrying an electrical charge sufficient to deter crossing the boundary.  

Well, how have you arranged the fence?"

"I start twelve immensely strong wires--naked, not insulated --from a big dynamo in the cave--dynamo with no brushes except a positive and a negative one--"

"Yes, that's right."

"The wires go out from the cave and fence in a circle of level ground a hundred yards in diameter; they make twelve independent fences, ten feet apart--that is to say, twelve circles within circles--and their ends come into the cave again."

"Right; go on."

"The fences are fastened to heavy oaken posts only three feet apart, and these posts are sunk five feet in the ground."

"That is good and strong."

"Yes. The wires have no ground-connection outside of the cave. They go out from the positive brush of the dynamo; there is a ground-connection through the negative brush; the other ends of the wire return to the cave, and each is grounded independently."

"No, no, that won't do!"

"Why?" "It's too expensive--uses up force for nothing. You don't want any ground-connection except the one through the negative brush. The other end of every wire must be brought back into the cave and fastened independently, and _without_ any ground-connection. Now, then, observe the economy of it. A cavalry charge hurls itself against the fence; you are using no power, you are spending no money, for there is only one ground-connection till those horses come against the wire; the moment they touch it they form a connection with the negative brush _through the ground_, and drop dead.

From A Connecticut Yankee in King Arthur's Court, by Mark Twain.
Published by Not known in 1889
Additional resources -

Many sources credit Twain as the earliest source for this idea - but I think there is at least one earlier reference that should count.

In his 1875 epic 20,000 Leagues Under the Sea, Jules Verne writes about electrifying a stair rail or cable to prevent unwanted intrusions onto the Nautilus.

Comment/Join this discussion ( 2 ) | RSS/XML | Blog This |

Additional resources:
  More Ideas and Technology from A Connecticut Yankee in King Arthur's Court
  More Ideas and Technology by Mark Twain
  Tech news articles related to A Connecticut Yankee in King Arthur's Court
  Tech news articles related to works by Mark Twain

Articles related to Security
Flimmer Navy Drone Flies And Swims
Indian Court Says Brain Scan Proves Murder
Background Draw-a-Secret (BDAS) Makes Graphical Passwords
ID-U Biometrics Eye Tracking Signature

Want to Contribute an Item? It's easy:
Get the name of the item, a quote, the book's name and the author's name, and Add it here.

<Previous
Next>

Google
  Web TechNovelgy.com   

 

 

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

More News

Sleeep PRO Earplug For Maximum Rest
'Merton... placed the electrodes of the sleep-inducer on his forehead.'

Inspired By Japan, Nap Pods For Hajj
It's always a good time for a nap.

Amphibio 3D Printed Gill Shirt
'... we can descend and live down there at one of those year-round aquatic resorts.'

How Do You Put An Asteroid Into Earth Orbit? Carefully!
'...she would have to be coaxed by another series of pats into a circular orbit.'

PD Aerospace Space Plane By 2023
'The sleek, tapered space shuttle lay immobile upon the private landing field...'

Foldimate Folds Your Clothes Perfectly
Look ma, my room is clean! I can hear you now.

Robots Help People Get Dressed, As Predicted In 1931
Yes, people of the future, robots will dress you.

International Space Station Leak Plugged - With Finger
'These tag-alongs search out stray leaks.'

Robot Snake Flies, Fights Fires
Just a prototype, but still amazing.

IPAL Chinese Robot Babysitter
'But Nanny is different...'

More SF in the News

More Beyond Technovelgy

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.