Assertion: galvanometer's magnet | /r/AtLocation | lightweight mirror
Facets:
Source sentences:
text: Thomson's design was able to detect very rapid current changes by using small magnets attached to a lightweight mirror, suspended by a thread, instead of a compass needle.
text: Thomson's design was able to detect very rapid current changes by using small magnets attached to a lightweight mirror, suspended by a thread, instead of a compass needle.