,26 A HISTORY OF ART ix CIIALU^EA AND ASSYRIA. All these manoeuvres are remarkable for the skill and prodigality with which human strength was employed ; of all the scientific tools invented to economise effort and to shorten the duration of a task, the only one they seem ever to have used was the most simple of all, the lever, an instrument that must have been invented over and over again wherever men tried to lift masses of stone or wood from the ground. Its discovery must, in fact, have taken place long before the commencement of what we call civilization, although its theory was first expounded by the Greek mathe- maticians. FIG. 152. Putting a bull in place ; from Layard. In a relief in the palace of Assurnazirpal at Nimroud, there is a pulley exactly similar to those often seen over a modern well. 1 A cord runs over it and supports a bucket. There is no evidence that the Assyrians employed such a contrivance for any purpose but the raising of water. We cannot say that they used it to lift heavy weights, but the fact that they understood its principle puts them slightly above the Egyptians as engineers. 1 LAYARD, Nineveh, vol. ii. p. 32.
