John’s Curious Machines

(John Harrison (1693-1776) devoted his life to solving the ‘Longitude Problem’:
to build a clock that can keep time in the humidity and motion at sea.)


Adrift on dead reckoning, I hanged a sailor who warned me
the Scillies would rise in fog to drown two thousand men.
He swung for mutiny, gainsaying his Admiral, the day before I died.
I washed ashore wrung out with regret: not sucked down
by the black Atlantic with my fleet, but beached – killed
for my emerald ring, by a woman. She could have had my finger
but chose to leave no witness. John Harrison was then fifteen.

Thirty years on, Centurion fought a two-month ice storm,
ribboning her sails past Cape Horn. Each night scurvy culled
a man an hour. Ship and wind spent, she aimed blind
for Juan Fernandez along 35° South:
four days west, then back; two days east until Chile walled her in.
Turning again, the Commodore despaired. Half her crew
bled out below deck for want of her longitude.

John could not yet save them, conjuring seven hundred parts
for his ‘curious third machine’. He hermited away two decades.
His first clock had sailed to Lisbon, horology pitched
against old ways of guesswork, calculation flaws
and half-blind sailors, one retina burned gauging lines
from moon to sun. His second’s grasshopper escapement
trapped near-perfect time for no one. Men swore by the stars.

John believed in earthly time and vowed to coax it through his box.
Caged ball bearings rubbed out friction. One strip of brass and steel
broke the tyranny of temperature over gridiron pendula.
Twenty years to build! His third stood primed to pin ships on the sea,
but John forged those apprenticed years into a new wonder.
Barely two years on, his fourth was born: a jewelled miniature.
Rubies and diamonds rocked time quiet between them.

The Deptford bore it to Jamaica, counting crescent and gibbous moons
through half a year of pitch and toss, heat and rough weather.
John’s son endured fevered sleep in The Watch’s salty blankets
but – dry – it erred just two minutes. Still the Longitude Board
refused to pay. John’s fifth and last went to the King. It proved
its forebears but stoked Maskelyne’s fury: his jealous star-gazers
threw John’s clocks on an unsprung cart and locked them up.

John died old, 7 minutes 35 seconds west of his chronometers.
They were forgot. Decades of sediment layered his precision;
rust and grease silting their geometry. Time nearly broke them.
A war-cracked man found their smudged intricacy;
mirrored their fragility. For twelve years he was patient
and healer, repaid by a slow synchronised return to motion.
Greenwich has them still, ticking out our time from the prime meridian.