Heliograph

The Heliograph is basically a mirror that uses the light from the sun to flash a message across a distance, often using morse code. They were widely used in the 19th and early 20th centuries for military and also for surveying purposes. Advanced models came with a tripod. Signals could routinely be sent over distances of 30 miles or more. The equipment was light and did not need any electrical power. However anyone in or near the line of sight could potentially read the message! Although they are no longer in common use, they are frequently supplied as part of emergency survival kits, allowing the user to signal to a distant ship or airplane. This 4 inch metal Heliograph is light and strong, and being made of metal will not easily break. Apart from being useful in emergencies, the mirror is also useful for shaving (as soldiers have long known!) or adjusting make-up. This Heliograph is from one of the UK suppliers of emergency survival kits, and the fascinating thing for us is the simple physics involved in the aiming mechanism. If you simply use a mirror to reflect light for a short distance you will be able to see the bright reflection, and direct it where you want. However at any distance, this will not work, and an aiming mechanism is needed. The Heliograph has a small hole, with a series of concentric circles arranged around the hole. There is a small sighting device, attached by a piece of string, and this has a small hole in one end. The user holds the mirror up to their eye, and holds the sighting device as far away as the string will allow. Line up the hole in the sighting device with the place where you want to shine the light, and then adjust the mirror so that the small black circle caused by the viewing hole in the mirror, exactly lines up with the hole in the aiming device. You will now be shining the reflection of the sun's light in exactly the direction you have chosen. Hopefully rescue will not take too long! You will see how to aim the Heliograph in the video. The mirror is 4 inches square, and it has instructions on the reverse side. See http://www.grand-illusions.com/acatalog/Heliograph.html

TARGET AD 2
2011/06/10 Grand Illusions   Share on Facebook

RELATED VIDEOS

The Magic Match!
Play Video

The Magic Match!

2011/09/28
Solar Balloon
Play Video

Solar Balloon

2012/02/20
FunFlyStick
Play Video

FunFlyStick

2008/10/13
Toys from Paris - part 1
Play Video

Toys from Paris - part 1

2008/07/09
London Panorama Optical Illusion
Play Video

London Panorama Optical Illusion

2008/07/09
Fascinating Ada
Play Video

Fascinating Ada

2015/10/07
Trick Dispensing Machine
Play Video

Trick Dispensing Machine

2012/02/24
The Riddle of the Sands
Play Video

The Riddle of the Sands

2015/07/15
Candle Stirling Engine
Play Video

Candle Stirling Engine

2011/03/16
Tim plays Russian Chess...
Play Video

Tim plays Russian Chess...

2014/12/07
Shtox glass
Play Video

Shtox glass

2011/10/31
Heatmobile
Play Video

Heatmobile

2011/03/16
The Mighty Dollar
Play Video

The Mighty Dollar

2008/07/10
Tim
Play Video

Tim's Russian Toys

2017/08/23
Tim Sweats the Small Stuff...
Play Video

Tim Sweats the Small Stuff...

2015/05/27
Ice Heart Maker
Play Video

Ice Heart Maker

2011/05/05
Torofluxus
Play Video

Torofluxus

2011/10/10
Weavogram Picture Toy
Play Video

Weavogram Picture Toy

2012/07/20
Tesla Valve
Play Video

Tesla Valve

2015/05/12
Eulers Disc
Play Video

Eulers Disc

2011/02/05
Tim
Play Video

Tim's Finger Fidgets - Part 1

2017/06/22
Topnosis
Play Video

Topnosis

2012/03/11
Atomic Trampoline
Play Video

Atomic Trampoline

2011/02/05
Tim Exercises His Prerogative...
Play Video

Tim Exercises His Prerogative...

2015/04/02
Unusual Toy Automata
Play Video

Unusual Toy Automata

2012/05/22
Thunderclapper
Play Video

Thunderclapper

2014/01/12
Miniature Automata
Play Video

Miniature Automata

2012/02/28
Nail Through Balloon Trick
Play Video

Nail Through Balloon Trick

2012/03/04
Tim says Snakes Alive! Part 2
Play Video

Tim says Snakes Alive! Part 2

2017/04/05
Magnetic Raketti - a trick within a trick!
Play Video

Magnetic Raketti - a trick within a trick!

2012/07/13
Sand pendulums - Lissajous patterns - part one // Homemade Science with Bruce Yeany
Play Video

Sand pendulums - Lissajous patterns - part one // Homemade Science with Bruce Yeany

2017/03/28
Tricky Animals Toy
Play Video

Tricky Animals Toy

2013/01/23
Toys from 1992
Play Video

Toys from 1992

2009/11/10
Tim Rattles his Rattlebacks
Play Video

Tim Rattles his Rattlebacks

2015/06/11
Amazing Discovery With Magnets
Play Video

Amazing Discovery With Magnets

2013/01/11
Hats off for Tim - Part 1
Play Video

Hats off for Tim - Part 1

2014/06/15
Steam Powered Top
Play Video

Steam Powered Top

2011/02/05
Gaussian Gun - a nice physics toy with magnets and ball bearings
Play Video

Gaussian Gun - a nice physics toy with magnets and ball bearings

2012/03/01
Cheating Cards
Play Video

Cheating Cards

2008/07/11
Solids of constant width
Play Video

Solids of constant width

2011/05/05
Crazy Glasses
Play Video

Crazy Glasses

2008/07/09
Tim
Play Video

Tim's Cat Toys - Part 3

2017/11/10
Tim has a Wobbly
Play Video

Tim has a Wobbly

2016/05/18
How small a hole can a mouse get through?  Experiments.
Play Video

How small a hole can a mouse get through? Experiments.

2017/12/08
Tim
Play Video

Tim's Nestling Sets

2017/05/25
Make Non Stop Heron’s Fountain With Plastic Bottle
Play Video

Make Non Stop Heron’s Fountain With Plastic Bottle

2017/10/11
Free Energy with Neodymium Magnet - Crisium
Play Video

Free Energy with Neodymium Magnet - Crisium

2017/06/25
Powered by YouTube

Disclaimer

None of the audio/visual content is hosted on this site. All media is embedded from other sites such as GoogleVideo, YouTube etc. Therefore, this site has no control over the copyright issues of the streaming media.

All issues concerning copyright violations should be aimed at the sites hosting the material. This site does not host any of the streaming media and the owner has not uploaded any of the material to the video hosting servers. Anyone can find the same content on Google Video or YouTube by themselves.

The owner of this site cannot know which documentaries are in public domain, which has been uploaded to e.g. YouTube by the owner and which has been uploaded without permission. The copyright owner must contact the source if he wants his material off the Internet completely.