What you need
A torch, or a phone light
The printed morse card
A friend
Somewhere dark
How to build it
Cut out the cardFold it once and put it in a pocket. Both of you need one.
Agree the speed firstSlow. A dot is about one second at the start, and a dash is three.
Cover the light between lettersA gap as long as three dots means a new letter. Seven means a new word.
Send your nameLetter by letter. Wait for them to send it back before you go on.
Then try it round a cornerBounce the light off a wall or a ceiling. The message still gets there, which is the whole point of light.
Never shine a torch straight into anybody’s eyes, and never at a car or a road.
The template
Print this at 100 per cent, not fit to page, or the sizes will be wrong. The ruler line below tells you whether it printed correctly.
The bar above should measure exactly 10 centimetres. If it does not, your printer has shrunk the page.
Now send something
Send SOS first, because everybody recognises it. Then send a word only your friend would guess.
Where it comes from
Any dark garden
The cheapest long-distance message there is
A lamp with a shutter, and morse. Ships still carry one, because two vessels can talk without a radio transmission that anybody within a hundred miles could pick up. It needs no wire to cut and leaves nothing behind afterwards.
Why it works
Light is the fastest thing there is and it leaves no trace. But everyone in the beam can read it, so a lamp carries a message and cannot keep one. That is why lamp messages were sent in code as well as in morse.
When it goes wrong
It usually does, the first time. Almost always one of these.
Your friend cannot tell dots from dashesSlow down and exaggerate: a dash should be obviously three times a dot.
Letters blur into each otherCover the light for three dots between letters and seven between words.