| 摘要 |
A transparent measuring device for topographical maps is graduated for converting a particular map scale in units of yards and/or fractions of a mile. The measuring device has a substantially rectangular body having a first, second and third top face, a first and second side surface and a bottom surface. The third top face is disposed between said first and second faces as a distinct magnifier. The first top face has a graduated scale including indicia for designating a measuring scale in units of yards. The second top face has a complimentary graduated scale including indicia for designating a measuring scale in units of miles which is directly correlated with measurements made in units of yards on the first face by a scalar conversion factor. A plurality of the measuring scales are attached at single point as and forms a unitary kit of measuring devices for measurements requiring different scales.
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