Sailors in Nelson’s navy were entitled to a daily rum ration as part of their pay.
To make sure the rum hadn’t been watered down too much, the crew would test a sample from the barrel by pouring it over gunpowder. This process was called ‘proving’. If the gunpowder failed to ignite, it meant the rum contained too much water.
So the navy carried out experiments to determine the lowest concentration of alcohol at which the gunpowder would still ignite. They calculated it at four parts alcohol to three parts water (57.15% Alcohol by Volume in today’s language).
From then on, rum containing that percentage of alcohol was deemed to be ‘100 proof’, a measure which became the standard benchmark for alcoholic strength in the UK until 1980.
It’s a handy pub quiz fact. It’s also a fascinating example of the value of trust in employee relations.
Because the officers on board knew they could be confident the rum would ignite, they embraced the idea of the proof test and turned it into a public display. Which meant it stopped being a point of contention and mistrust for the crew – and, instead, became a repeated celebration of their employers’ integrity.
The Royal Navy became known for the morale and discipline of its crews and, as a result, their superior skills in seamanship and gunnery. Which allowed the British to defeat even their more powerful enemies, dominate the world’s oceans and establish the largest empire ever seen. All without spending a single penny more than they were contractually obliged to (because their rum rations were as efficient as they could possibly be).
Next time your finance director asks you why it’s worth investing in engagement, you might want to tell them this story.