Assertion: torch | /r/ObjectUse | used for welding magnesium
Facets:
value: successfully
type: MANNER
value: until november of 1942
type: TEMPORAL
Source sentences:
text: The torch was used successfully for welding magnesium until November of 1942 when Northrup invented the “Heliarc” to combat the problem of excess oxygen in the torch flame which would cause the magnesium to burn.