'Round and 'round she goes, and where she stops nobody knows

(sculpture, head of Janus in Vatican museum, CC BY-SA 3.0)

Janus am I; oldest of potentates;
Forward I look, and backward, and below
I count, as god of avenues and gates,
The years that through my portals come and go.

I block the roads, and drift the fields with snow;
I chase the wild fowl from the frozen fen;
My frosts congeal the rivers in their flow,
My fires light up the hearths and hearts of men.
--Henry W. Longfellow


Old things need not be therefore true,
O brother men, nor yet the new;
Ah! still awhile the old thought retain,
And yet consider it again

The souls of now two thousand years
Have laid up here their toils and tears,
And all the earnings of their pain,--
Ah, yet consider it again!

We! What do we see? each a space
Of some few yards before his face;
Does that the whole wide plan explain?
Ah, yet consider it again!

Alas! the great world goes its way,
And takes its truth from each new day;
They do not quit, nor can retain,
Far less consider it again.
--Arthur Hugh Clough