请将下面这段话翻译成英文：

　　中国历史博物馆的展厅里,陈列着第一台地动仪 (seismograph)的修复模型。 发明者是东汉著名的科学家张衡。公元132年,在当时的都城洛阳,张衡发明了古代的地动仪(seismograph),以辨别地震的方向。地动仪由纯铜制成,看起来像个带盖的大杯子。其表面铸有八条龙,每条龙口含一颗铜珠。每条龙的下方都有一只仰头的铜蟾蜍(toad),张口对着龙的嘴巴。人们十分尊敬张衡这位伟大的科学家,并常常举行纪念活动表达对张衡的尊敬之情。月球上的一座环形山(crater)就是以张衡的名字命名的。

　　参考翻译

　　In the exhibition hall of the Museum of Chinese History in Beijing,there is a restored model of the first seismograph.The inventor was Zhang Heng,a famous scientist in the Eastern Han Dynasty.In 132 A.D,in the then national capital Luoyang,Zhang Heng made the ancient seismograph to identify the direction of an earthquake.It was made of fine copper,and looked like a big cup with a lid.The instrument was cast with eight dragons on the surface,and each dragon held a copper ball in the mouth.On the ground below the dragons,there were eight copper toads raising their heads and opening their mouths opposite the dragons'mouths.People highly respect Zhang Heng as a great scientist,and they often hold commemorative activities to show respect for him.A crater on the moon was named after him.