Since then-tis Centuries-and yet Feels shorter than the Day I first surmised the Horses' Heads Were toward Eternity -

This excerpt appears to be from Emily Dickinson's poem "Because I could not stop for Death." It reflects on the passage of time and the inevitability of death. The speaker contemplates the centuries that have passed since a certain moment, and yet, the experience feels shorter than the initial day of realization. The mention of "Horses' Heads" suggests a carriage, symbolizing the journey towards eternity or death. The poem explores themes of mortality and the perception of time.