钟表玻璃及钟锤（按其构成材料归类）；
Clock or watch glasses or weights (classified according to their constituent material);
现在所使用的钟锤，其重量只有190公斤。
在1500年初用发条代替钟锤来驱动时钟发明后不久，就出现了第一批表。
The first watches appeared shortly after 1500, when the mainspring was invented as a replacement for weights in driving clocks.
应用推荐