Cat's eye sundial  貓眼日晷

http://web-japan.org/museum/others/ninja/ninja03/wisdom02.html

Cat's eye sundial

The sand glass was the tool used most often by "ninja" for establishing the time of day. However, they also used another method for this purpose. The cat's eye sundial is a method for telling the time by the aperture of a cat's eye. The eyes of a cat look fully round and open during the twilight periods at daybreak and sunset. They reduce in size to a near-oval shape between 8:00 and 16:00, and even more so at between 10:00 and 14:00. At 12:00 noon they become extremely narrow almost needlelike in a straight line. The "ninja" used this type of sundial because they knew the properties of cat's eyes very well. As seen above, the "ninja" were experts at various martial arts and made free and full use of their knowledge including artillery, astronomy, meteorology and the ecology of animals and plants.

日晷

砂玻璃是用於建立一天中的時間最經常使用的“忍者”的工具。然而，它們也可用於另一種方法，用於此目的。貓的眼睛日晷是由貓眼的孔徑告訴時間的方法。貓的眼睛看起來十分全面和開放的過程中黃昏時段在破曉和日落。它們的尺寸縮小到近橢圓形8:00至16:00之間，更應如此，在與10:00和14:00。中午12時，他們變得非常狹窄的針狀幾乎在一條直線上。在“忍者”使用這種類型的日晷，因為他們知道貓的眼睛的特性非常好。由上可見，在“忍者”是專家們在各種武術，並取得了自由和充分利用，包括火炮，天文，氣象，動物和植物的生態學知識。

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