Analysis of A light exists in spring

A light exists in spring
   Not present on the year
At any other period.
   When March is scarcely here

A color stands abroad
   On solitary hills
That science cannot overtake,
   But human naturefeels.

It waits upon the lawn;
   It shows the furthest tree
Upon the furthest slope we know;
   It almost speaks to me.

Then, as horizons step,
   Or noons report away,
Without the formula of sound,
   It passes, and we stay:

A quality of loss
   Affecting our content,
As trade had suddenly encroached
   Upon a sacrament.