Through the strait pass of suffering —

Through the strait pass of suffering —
The Martyrs — even — trod.
Their feet — upon Temptations —
Their faces — upon God —

A stately — shriven — Company —
Convulsion — playing round —
Harmless — as streaks of Meteor —
Upon a Planet’s Bond —

Their faith — the everlasting troth —
Their Expectation — fair —
The Needle — to the North Degree —
Wades — so — thro’ polar Air!

Emily Dickinson

The poem describes a slowly changing pattern of aurora in the polar zone. The third line of the second stanza “The Needle — to the North Degree” is a critical hint.

The Martyrs trod further
Through the narrow pass
Feeling intolerable pain,
Although their feet are on temptations,
Their faces are on God.

A stately shriven company
Goes into convulsion,
They are innocent as beams of meteor 
On a Planet’s Bond —

Their faith, that is, the everlasting troth 
And their expectations are fair.
The Needle pointing to the North Pole
Advances on foot through’ polar Air!