[ALL transparent bodies have the power of decomposing the light which falls on them. A soap-bubble, for example, exhibits a beautiful play of colours on its surface; and so is it with that most beautiful of all the phenomena of the atmosphere, the rainbow. The drops of rain act as a prism, and separate the white light of the solar rays into the seven prismatic colours of which sunlight is composed-namely, violet, indigo, blue, green, yellow, orange, and red; the dark cloud behind the falling shower acting as a screen, on which the brilliant arch is made visible to the spectator.]
TRIUMPHAL arch, that fill"st the sky When storms prepare to part!
I ask not proud philosophy To teach me what thou art:
Still seem, as to my childhood"s sight, A midway station givenFor happy spirits to alight Betwixt the earth and heaven.
Can all that optics
teach unfold
Thy form to please me so,
As when I dreamt of gems and gold Hid in thy radiant bow?
When science from Creation"s face Enchantment"s veil withdraws, What lovely visions yield their placeTo cold material laws!
And yet, fair bow, no fabling dreams, But words of the Most High,Have told why first thy robe of beamsWas woven in the sky.
When o"er the green undeluged earth Heaven"s cov"nant thou didst shine,How came the world"s gray fathers forth To watch thy sacred sign!
And when its yellow lustre smiled O"er mountains yet untrod,Each mother held aloft her child, To bless the bow of God.
The Earth to thee her incense yields, The lark thy welcome sings,When, glittering in the freshened fields, The snowy mushroom springs.
How glorious is thy girdle, cast O"er mountain, tower. and town;Or mirrored in the ocean vast, A thousand fathoms down!
As fresh in yon horizon dark, As young thy beauties seem,As when the eagle from the ark First sported in thy beam.
For, faithful to its sacred page, Heaven still rebuilds thy span,Nor lets the type grow pale with age That first spoke peace to man.
- THOMAS CAMPBELL
