双语科技百科(天文) 第9期:张衡和地动仪
Zhang Heng and the Seismograph
In the Exhibition Hall of the Museum of Chinese History in Beijing，there is a restored model of the first seismograph,which was called Houfeng Didong Yi(lit. an instrument for measuring the seasonal winds and the movements of the Earth) inventor was Zhang Heng，a famous scientist in the Eastern Han Dynasty.
在北京中国历史博物馆的展览大厅里，陈列着世界上第一架地动仪的复原模型。这架地动仪的发明者是中国东汉时著名的科学家张衡。Zhang Heng was from Nanyang of Henan Province. He studied diligently，andwas especially fond of astronomy，calendar and mathematics.
张衡，河南南阳人。他勤学好问，博览群书，特别爱好天文、历法和数学，是一位博学多才的科学家。
During the Eastern Han period，earthquakes occurred frequently. Contrary to the popular belief at that time，Zhang Heng maintained that earthquakes were not signs of Heaven’s anger but natural disasters.
东汉时期，地震很活跃。当时的人们不懂科学，以为地震是鬼神发怒。张衡认为地震是一种自然灾害，As a result of careful observations of earthquakes，he invented a seismograph in the then national capital of Luoyang in 132 AD，which was the world’s first instrument to identify and ascertain the direction of earthquakes.
他根据自己对于地震现象的观测，于公元132年在京城洛阳制成了“候风地动仪”，这台仪器成为世界上第一台观测地震方向的仪器。The seismograph was made of fine copper, and was ingeniously constructed. Inside，there was a balanced post and eight rods.
地动仪全部用精铜铸成，结构非常精细巧妙。仪器内部竖有一根铜柱，周围有8根杆子。Outside，it was cast with eight dragons on the surface(whose heads pointed in eight diredions-east，south，west, north，southeast, northeast，southwest，and northwest )，and each dragon had a copper ball in the mouth.
仪器表面铸有八条垂直向下的龙，龙头分别对准东、南、西、北、东南、东北、西南、西北八个方向，每条龙的嘴里都含着一个铜球。On the ground below the dragons there were eight copper toads raising their heads and opening their mouths oppo-site the dragons’ mouths. When an earthquake occurred，the balanced post in the direction of the quake and push a rod.
在对着龙嘴的地上，蹲着八个仰着头、张着嘴的铜蟾赊。当某个方向发生地震时，柱子就倒向那个方向，触动杆子，仪器上对着那个方向的龙嘴就会张开，The dragon facing that direction would open its mouth，and the ball would fall into the mouth of the toad below, automatically indicating the direction of the day in 138 AD，the dragon in the west expelled its ball.
铜球就会掉进铜蟾蛛的嘴里，自动报告发生地震的方向。公元138年的一天，地动仪西边的龙嘴吐出了铜球。As expelled，an earthquake had oc-curred that day in Longxi(present-day Western Gansu Prov-ince ) a thousand kil-ometers away. It was the first time that mankind had used an instrument to detect an earthquake. It was over 1,700 years later that a similar in-strument was invented in Europe.
果然，远在千里之外的陇西(今甘肃西部一带)在这一天发生了地震。这是人类第一次用仪器测报地震。在欧洲，直到1700多年后，才发明了同类的仪器。Unfortunately，the seismograph has not been handed may have been lost after the Yongjia Turbulence in Western Jin Dynasty(307一312) origi-nal shape can only be inferred from documents like Eastern Han Dynasty Records and History of East Han Dynasty.
遗憾的是，地动仪未能流传下来，可能是在西晋永嘉之乱(307一312 )之后失落的，现在只能从《后汉记》、《后汉书》等文献中推测它的原貌。Zhang Heng was also a mechanical engineer. He ever made a flying “wood-en eagle” and a“mileage-counting drum-cart”.
张衡还是一位机械工程师，制造过能飞的“木雕”和能计算里程的“计里鼓车”。People highly esteem Zhang Heng，a great scientist living more than 1，800 years ago，and they often hold commemorative activities to show respect for him.A ring of hills on the moon was named after him.
人们非常敬重张衡这位1800多年前的大科学家，经常举行纪念活动，表示对他的敬意。月球上有一座环形山是以他的名字命名的。
