Steaming mammoth Hot Springs, Yellowstone National Park - among the highest energy of the hot springs in the park and highest heat flow sites, the terraces are made of carbonate minerals (most of the other hot springs in the park flow through silicate minerals and precipitate silica sinter).
If you see a geyser just as it’s about to
erupt, it might look like some sort of alien
egg is about to hatch from the earth. As
the super-heated water below ground
turns immediately to steam, bubbles
rise and pressure builds- but for a split
second before the geyser erupts, you can
often see a giant bubble that catches the
light as it forms over the fissure. SourceSource 2
“The Metropolitan Water Works’ Chestnut Hill High Service Pumping Station, built 1886-87 and expanded in 1897-98, was built at the height of what is sometimes called Boston’s Golden Age, a period of great prosperity for Boston and New England, lasting from the Civil War through World War I.