Left: eyes on sentry-duty, asking ‘who goes there?’ Right: same guarded look; of course the same piping on the tunic and the same cap, oddly-oversized.

Bus conductor? Russian admiral? No, it’s Thomas Highgate of the Royal West Kent Regiment, first British ‘deserter’ to face a First World War firing squad, 99 years before last night’s Last Night of the Proms.

When they sing ‘Rule Britannia’, Tommy, do you turn in your unmarked grave?

It’s the mouth that’s different. Though in both instances, Highgate’s lips are slightly apart, in the left-hand picture the former farm labourer’s mouth is ‘set on’, as employers and foremen used to say of their underlings: expectant, alert; ready to do his bit. Yet on the right the same mouth seems to be slackening, slackened, slack.

(Looking at these pictures online, I first thought that they were one and the same; only the sepia tint had made them seem different. On closer inspection, I noticed that in one picture alone the hat is higher than the slatted background; but I don’t know whether these two shots were taken in quick succession or on separate occasions.)

In the eyes of the officer class, the face on the left could still be trusted to join in with William Blake’s ‘Jerusalem’, inspired – it is said – by the Kent landscape which Private Highgate grew up in.

If you’d made it home, Tommy, you would have seen the Battle of Britain in the skies above Shoreham. It could have been you in the Home Guard in 1940, rounding up the crew of a German bomber shot down over Castle Farm; giving them a tot of brandy before handing them over to the Army.

Face on the right: no harmony here, no possibility of returning to Sunday matins or Promenade concerts at the Queen’s Hall; any sound emitted will only be the shriek of a Schoenberg.

Agonising for the other men, sir!

Faced with Highgate’s two faces, uncertain which would be the winning side amongst their own side, the officers of the court martial opted to close his mouth permanently.

Quick trial, quick march, quickly shot. But make sure there are plenty of witnesses from neighbouring regiments, understood?