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发表于2024-11-29
Making a Clock-Accurate Sundial pdf epub mobi txt 電子書 下載 2024
Sundials have been around for ages, but Sam Muller's is specially Customized to Your Location, easy to make and use from his diagrams and directions. By its shadow you can read correct time, and observe the effects of the earth's tilt, rotation, and changing orbital speed. On a moonlit night, from the shadow cast on your now 'moondial, ' you will notice the moon's counterclockwise orbit of the earth.
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Making a Clock-Accurate Sundial pdf epub mobi txt 電子書 下載 2024