I Felt a Funeral, in My Brain

"And then a Plank of Reason, broke,
And I dropped down, and down -
And hit a World, at every plunge,
And finished knowing - then -"

First of all, the poem is broken up into quatrains.  I believe the author did this because it makes the poem flow better.  She also rhymed every other line of the quatrain which also contributes to the purpose the author chose to write like this.  This poem is funeral-like in the beginning with "mourners to and fro," "all were seated," and a Service "beating" like a drum.  Then, it goes into discussing the afterlife.  The person hears Heaven bells, but then it's silent and solitary.  Next, I believe it discusses either going to Hell or there being no afterlife after all.  It describes that "a Plank of Reason broke," someone is "dropped down," and hitting a "World at every plunge."  The poem ends by saying that the person "finished knowing."  I think that means that the person is completely done living whether that be in Hell or just gone forever.