Device for measuring distances on globes or maps

摘要

A map or globe is provided with a transparent thin covering capable of conducting electricity. The transparent thin covering envelopes the globe or overlies the map. An electrical resistance measuring means would be employed to determine a measure of electrical resistance between any two points on the map or globe. The electrical resistance measuring means would include a first probe and a second probe. The first probe would be placed on a first location on the map or globe and the second probe would be placed on a second location on the map or globe. A measure of electrical resistance will be generated by the electrical resistance measuring means reflecting the resistance of the conductive thin covering between the first location and the second location. This electrical resistance is proportionally related to the distance separating the two points on the map or globe. The measured resistance may then be processed by processing means to permit an accurate measurement of the distance between the two points to be output in a digital fashion. This numerical digital output may be in any conventional distance scale which would be related directly to the scale of the map or globe employed.