The Time Machine - Chapter 8 - Explanation

The Time Traveller explores peculiar circular wells with a thud-thud-thud sound coming from them, and tall towers with a flicker of heat above them. He concludes that there is an extensive system of subterranean ventilation, but is unable to learn much more due to the gap between his own knowledge and that of the society he is visiting. He is also puzzled by the lack of cemeteries, elderly and infirm people, and machinery or appliances of any kind. He eventually discovers the cause of the wells and towers, but not before putting forward several theories of his own. 

He rescues one of the Eloi from drowning, and she becomes his friend. This gives him further insight into the society and his realisation that feat has not actually left this world.

 The Time Traveller also discovers that the Morlocks are responsible for stealing his Time Machine and he begins to uncover the mystery behind their existence and the purpose of the underground world. He also begins to understand the relationship between the two species and why the Eloi are so afraid of the dark. In the end, he believes that the Morlocks have been living underground for a long time and are the ones responsible for the work necessary to sustain the Eloi's lifestyle.