What does thoreau use as a metaphor for government

The correct answer is a “machine.”  

What Thoreau uses as a metaphor for government is a “machine”.

In 1846, Henry David Thoreau considered the declaration of war on Mexico as a plot from the people from the South to increase slavery in the region. In protest, Thoreau stopped paying taxes and he was arrested. That is why he wrote the “Civil Disobedience” in July. The text was published three years after with the name “Resistance to Civil Government”. In the text, Thoreau uses the metaphor “machine” to refer the government.  

it would have to be gasioline

it's lower nubia : ) good luck