What is called modern history is in reality the formation of a new cycle of culture, connected in several stages of its development with the perishing or perished civilization of the Mediterranean states, as this was connected with the primitive civilization of the Indo-Germanic stock, but destined, like the earlier cycle, to traverse an orbit of its own.
— from The History of Rome (Volumes 1-5) by Theodor Mommsen

Its cycle is: First outstroke, gas and air sucked into the cylinder; first instroke, gas and air compressed into space; second outstroke, impulse due to ignition; second instroke, discharge of exhausted gases.
— from Scientific American Supplement, No. 484, April 11, 1885 by Various