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

"At its best, SF is the medium in which our miserable certainty that tomorrow will be different from today in ways we can't predict, can be transmuted to a sense of excitement and anticipation, occasionally evolving into awe."
- John Brunner

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

Heart-In-A-Box Saves Organ For Later
'Storage in the hospital's organ banks...'

MultiFab 10-Material 3D Printer
'On the concrete platform, in front of the dying Biltong, lay a heap of originals to be duplicated.'

Chaac Ha Dew Collector ala Dune
'The surface condenses moisture out of the air. That moisture trickles down...'

Digital Immortality For Your Personality
'You've got remote storage. How regular is the update?'

Robots Take Our Jobs By Reading Our Instructions
'The Talk Between Robots radio...'

Surgery In Space
' It was a ... coffin, form-fitted to Nessus himself...'

Flimmer Navy Drone Flies And Swims
Launch the Flying Sub!

Taser Drones Now Legal In North Dakota
'I sent my eyes on their rounds and tended my gallery of one hundred-thirty changing pictures...'

Growing Metal In The Shape You Want
What more do you need, engineers?

Self-Healing Materials For Spacecraft
'It even had an inter-skin layer of gum that sealed the punctures...'

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.