So far as I know, Engels never rode the Underground, but he understood its spirit.  In The Condition of the Working Class in England , he wrote:

“Hundreds of thousands of people from all classes and ranks of society crowd each other [on the streets] . . . . Meanwhile it occurs to no one that others are worth even a glance.  The brutal indifference, the unfeeling isolation of each individual person in his private interest becomes the more repulsive and offensive the more these individuals are pushed into a tiny space.  We know well enough that this isolation of the individual, this narrow-minded self-seeking - is everywhere the fundamental principle of modern society . . . . From this it follows that the social war - the war of all against all - has been openly declared.  As in Stirner, men here regard each other only as useful objects.”

On his first visit to London, Dostoevsky had a similar impression.  The miserable isolation in the crowd manifested the “stubborn, dumb, deep-rooted struggle” that defined Western European societies, the struggle “of somehow establishing a society and organizing an ant-heap.”