our assurance surer.

For uncounted centuries before ever hearing of "Gravitation" men knew
of the sun that he rose and set at hours which, though mysteriously
appointed, could be accurately predicted; of the moon that she regularly
waxed and waned, drawing the waters of the earth in a flow and ebb, the
gauge of which and the time-table could be advertised beforehand in the
almanack; of the stars, that they swung as by clockwork around the pole.
Says the son of Sirach concerning them--

_At the word of the Holy one they will stand in due order,
And they will not faint in their watches._

So evident is this celestial harmony that men, seeking to account for it
by what was most harmonious in themselves or in their experience,
supposed an actual Music of the Spheres inaudible to mortals; Plato (who
learned of Pythagoras) inventing his Octave of Sirens, spinning in the
whorls of the great planets and intoning as they spin; Chaucer (who
learned of Dante and makes the spheres nine) in his _Parliament of
Foules_ telling, out of Cicero's _Somnium Scipionis_, how the great
Scipio Africanus visited his descendant in a dream and--

_Shewed he him the litel erthe, that heer is,
In regard of the hevenes quantite:
And after shewed he him the nyne speres,
And after that the melodye herde he
That cometh of thilke speres thryes-three
That welle is of musicke and melodye
In this world heer, and cause of armonye._

While Shakespeare in the last Act of _The Merchant of Venice_ makes all
the stars vocal, and not the planets only:

_There's not the smallest orb which thou beholdest
But in his motion like an angel sings,
Still quiring to the young-eyed cherubims..._

And Milton in _Arcades_ goes straight back to Plato (save that his
spheres are nine, as with Chaucer):

_then listen I
To the celestial Sirens' harmony
That sit upon the nine enfolded spheres
And sing to those that hold the vital shears
And turn the adamantine spindle round
Of which the fate of gods and men is wound.
Such sweet compulsion doth in music lie
To lull the daughters of Necessity,
And keep unsteady Nature to her law,
And the low world in measured motion draw
After the heavenly tune._

From the greater poets let us turn to a lesser one, whom we shall have
occasion to quote again by and by: to the _Orchestra_ of Sir John Davies
(1596), who sees this whole Universe treading the harmonious m