Eureka (word) "Eureka! Eureka!" after he had stepped into a bath and noticed that the water level rose, whereupon he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. (This relation is "not" what is known as Archimedes' principle—that deals with the "upthrust" experienced by a body immersed in a fluid.) He then realized that the volume of irregular objects could be measured with precision, a previously intractable problem. He is said to have been so eager to share his discovery that he leapt out of his bathtub
Eureka, Illinois Eureka. Eureka was originally laid out as "Walnut Grove" in 1855. The name was changed to "Eureka" because of a naming conflict with another Walnut Grove. Sources differ on who proposed the name Eureka. The city is named from the Greek expression Eureka, meaning "I have found it". Eureka is located at (40.715620, -89.275220). According to the 2010 census, Eureka has a total area of , of which (or 98.44%) is land and (or 1.56%) is water. As of the 2000 United States Census, there were 4,871 people, 1,754 households, and 1,169 families residing in the city. The population density