双环式日晷

　　日指太阳，晷表示影子。日晷是根据太阳在天空中的实际位置测定时间的一种仪器。此处展示的双环式日晷由子午环、赤道环和天轴组成。圆环直径4米，
总高5米。子午环上安置天轴与哈尔滨纬度45度相同，天轴高端指北。天轴在阳光照射下落入赤道环内侧的针影，即当时的真太阳时时刻。 
One pair of ring type sundials
    " Day" refers to the sun, the shadow cast by the sun expresses the shade,sundial is a kind of instrument of measuring time according to the sun actual position in the sky. One pairof ring type sundials shown here ismade up of noon enclose to sun, the ring of the equator and line shaft. The diameter of round ring is 4 meter. The total height is5meters. Noon enclose to sun places ling shaft and is the same as harbin 45 of latitude,height end of ling shaft points to north. In sunshine,line shaft prjects needle shadow of inproard of the equator surround,namely it is true time of the sun at that time.