TAILIEUCHUNG - An Encyclopedia of the History of Technology part 29

An Encyclopedia of the History of Technology part 29. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART TWO POWER AND ENGINEERING equipment which is to be powered outside the horse path. This form of horizontal machine is often to be found as a portable machine which can be taken round the farm to do various jobs. To the vertical and horizontal machines should be added two forms of animal-powered machines which are outside the above classification. In the oblique treadmill the animal usually a horse is harnessed firmly between two frames and stands on an obliquely-mounted belt which moves off from under his feet. The upper end of the belt is on the same shaft as a pulley wheel so that there is a considerable speeding up between the engine often called a paddle engine and the machinery which could be a circular saw or a threshing drum. The other oddity is the oblique treadwheel which consists of a fairly small-diameter circular tread plate which has treads fixed radially on its upper face. The underside of the oblique treadwheel carries a gear wheel from which the drive is taken and which is used for small tasks like churning butter. The ancient world We have considerable knowledge of the use of animal-powered engines in prehistoric and classical times but no certainty of their form until the Roman period. The use of the vertical treadwheel for hoisting purposes is shown in a relief in the Lateran Museum. This shows a treadwheel with at least four operatives inside. The windlass on the shaft of this treadwheel is lifting a stone by means of two two-sheave pulleys in order to give a further 4 1 lift in addition to the advantage of the treadwheel. Ropes pass from the treadwheel at the bottom of a single boom to lift a stone on to the roof of a temple. While this is not the only example the quality of this relief shows how skilled the Roman engineers were in being able to set up the treadwheel in a temporary setting such as a building site. The Romans were probably the originators of the hourglass animal-powered corn-grinding mill. There are examples of this form of

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