Assertion: bunsen burner | /r/AtLocation | extensive use
Facets:
value: for several years
type: TEMPORAL
Source sentences:
text: Although the Bunsen burner has been in extensive use for several years, there would seem to be a very well-grounded suspicion that its capabilities have not yet been fully discovered, for applications for patents for inventions, which are based on the Bunsen burner, or on modifications of it, are occasionally found in the official journal of the Patent Office.