If you sail due east from here across three and half degrees of longitude – one hundredth of the way round the Earth – you come in a few hours, or days perhaps, to the shore of the Dutch province of Holland.

A long stretch of sandy beach from the Hook of Holland up to the island of Texel and beyond.
In between, the seaside town of Scheveningen with its own pier and its own Kursaal.

A mirror world reflected by the North Sea.

‘Holland,’ wrote the English poet and MP Andrew Marvell, ‘scarce deserves the name of land, / As but th’ off-scouring of the British sand.’
And perhaps it does happen from time to time that some of the sand from Southend makes its way with the tide to be deposited on the dunes of the Holland coast, the mountains of the Netherlands.

In that province of Holland, within sight of Scheveningen beach, Marvell’s contemporary, the poet and diplomat Constantijn Huygens, picks up his pen. He looks, and he sees, and he writes: ‘The Lord’s benevolence shines from every dune.’

Sand.
Bright refractions from each silica grain beam the light of the Sun into our eyes. And the sand of the Dutch dunes has indeed shown its benevolence.
For it was on this not so distant, not dissimilar coast during the course of the seventeenth century that Dutch inventors and Dutch scientists perfected both the telescope and the microscope, using lenses made from glass made from sand. Macrocosm and microcosm were suddenly made visible.

Most sand can be used to make glass.
But for glass of optical quality, special sand is needed.
The right composition.
The right size and shape of the grains to be fused together. Sand and glass.

Constantijn’s son, Christiaan, and his brother ground their own glass lenses and used them to build their own telescopes.
The invention was warmly welcomed by the maritime Dutch.
Telescopes might be used for navigation or in military campaigns.

But the Huygens brothers turned their telescopes to the sky, and began to observe the Solar System.
Soon, Christiaan was able to detect for the first time the Ring of Saturn and its moon, Titan.

He observed the poles on Mars and the mountains on the Moon. He began to think about life on other planets…

But Christiaan was a true scientist, not a dreamer.
Observing the light refracted by crystals like the sand grains of the Dutch dunes, and inspired perhaps by the restless surface of the North Sea, he proposed a wave theory of light.
A wave theory of light more than a century before science was ready to embrace the idea.

Christiaan Huygens also invented the pendulum clock. One of the first of these he installed in the church tower at Scheveningen.
(Before this, time was often kept by measuring the sand running through an hourglass. Sand and glass and time.)

He hoped that sea-going versions of these clocks might be developed in order to solve the age-old problem of mariners’ knowing their longitude at sea.

That was many moons ago.
More than four thousand moons, in fact.
The same moon that raises the tides by the force of gravity, that agitates the sands and shifts them from beach to beach, that grinds the grains for the glass by which we can see the planets.
Sand and glass and time and place and the cosmos.