A metronome is also an obelisk. The symbol of all learning, of ancient Egypt. In the film 2001: A Space Odyssey, Stanley Kubrick makes his monument to evolution an obelisk.

It’s tempting to worship the confines of time, the bars of our cage.

How do you release the atoms of time, open the door simultaneously to the past and the future? As Auden says in his poem, “As I Walked Out One Evening”:

But all the clocks in the city
Began to whirr and chime:
O let not Time deceive you,
You cannot conquer Time.

In the burrows of the Nightmare
Where Justice naked is,
Time watches from the shadow
And coughs when you would kiss.

In headaches and in worry
Vaguely life leaks away,
And Time will have his fancy
To-morrow or to-day.

Into many a green valley
Drifts the appalling snow;
Time breaks the threaded dances
And the diver’s brilliant bow.

An obelisk is a vertical book, engraved with ancient wisdoms, usually in Egyptian hieroglyphics.