中文翻译与英英解释

长脚圆规，长径规。

beam:    n. 1.梁，栋梁，桁条；(船的)横梁。 2.船幅；(动 ...

compass:    n. 1.周围；界限，区域范围；【音乐】音域。 2.罗盘 ...

A beam compass is a compass with a beam and sliding sockets or cursors for drawing and dividing circles larger than those made by a regular pair of compasses. The instrument can be as a whole, or made on the spot with individual sockets (called trammel points) and any suitable beam.