The Cloud Factory is an affectionate nickname for a boiler plant which billows steam from below its single smoke stack in The Mysteries of Pittsburgh, the 1988 debut novel by the Pulitzer Prize-winning American writer Michael Chabon.
Source of the phrase 
Chabon may have coined the name "Cloud Factory" himself, or heard it first from locals before employing it to great effect in his novel. Or he may have borrowed the phrase from Henry David Thoreau. It appears in Thoreau's essay Ktaadn and the Maine Woods, which was first published in five serialized installments in Sartain's Union Magazine in 1848. The piece describes a transcendental, "mountain-top" experience Thoreau had in the summer of 1846 while hiking Mount Katahdin in Maine:
Sometimes it seemed as if the summit would be cleared in a few moments, and smile in sunshine; but what was gained on one side was lost on another. It was like sitting in a chimney and waiting for the smoke to blow away. It was, in fact, a cloud factory—these were the cloud-works, and the wind turned them off done from the cool, bare rocks.
External links 
Coordinates: 40°26′32″N 79°56′56″W / 40.4422°N 79.9490°W