Happy Birthday in Morse Code

This is a genuinely long message by Morse standards: forty-one dots and dashes, plus twelve letter gaps and one word gap. Counted properly it comes to about one hundred and forty time units.

At twenty words per minute, where one unit is sixty milliseconds, that is roughly eight and a half seconds. At a beginner's ten words per minute it takes about seventeen. At a contest operator's forty, just over four.

That arithmetic is worth seeing once, because it makes the whole timing system concrete. Every length in Morse is a multiple of one unit, and one unit is 1200 divided by the speed in words per minute. The Morse code timing has a calculator that does it for any speed.

HAPPY contains .--. .--., two P characters in a row. Like the double S in other phrases, this is where hand-made versions fall apart: eight elements that only split into two letters if the gap between them is clearly three units.

P is also one of the more confusable characters. It shares its four elements with L (.-..) and with a badly spaced A followed by N. Hearing two of them consecutively, at speed, is a fair test of whether you have the letter gaps internalised.

If you want to send this to somebody as audio, twelve to fifteen words per minute is a sensible choice: fast enough that the characters have their proper shape, slow enough that a recipient with a Morse code chart open can follow along.

• Thank you in Morse code
• I love you in Morse code
• Work out the send time for any speed