What is the author's tone in The Arsenal at Springfield by Henry Wadsworth Longfellow?

The tone is metaphorical. The most obvious technique that Longfellow uses is metaphor. The organ of war comes to life from the moment he describes the guns as a musical instrument. This thought is compelling, especially since it is a contradictory metaphor. The idea of using a peaceful instrument to describe items that are used to create violence immediately engages the reader's attention. However, Longfellow takes it several steps further by sustaining the metaphor.