From the archives: Everyday codes

Deciphering the codes of everyday life: car tyre codes, telegraph abbreviations, the hazardous substance Fire Diamond, and North American train whistle codes.

William Sidney Mount / Public domain

The Fire Diamond ranks the danger of various hazardous substances to fire fighters. But does any substance rank the highest in all its categories?


The markings on a standard car tyre encode an enormous amount of information.


Telegram messengers
Hine, Lewis Wickes / Public domain

The Phillips Code provided a standard set of abbreviations to save money and time sending telegrams. “POTUS” is still used today (although rarely for telegrams).


When a train blasts one long and three short whistles, it’s time to attach a torpedo to the tracks.

Leave a Reply