Other crater lakes of circular or oval form, and hollowed out of similar ancient strata, occur in the Upper Eifel, where copious aeriform discharges have taken place, throwing out vast heaps of pulverized shale into the air.
"The Student's Elements of Geology"
Sir Charles Lyell
Thus, given the original nebula, which, acquiring a vortical motion in the way indicated, has at length concentrated into a vast spheroid of aeriform matter moving round its axis-given this, and mechanical principles explain the rest.
"Essays: Scientific, Political, & Speculative, Vol. I"
Herbert Spencer
How can aeriform matter withstand such a pressure?"
"Essays: Scientific, Political, & Speculative, Vol. I"
Herbert Spencer