Assertion: balloon's envelope | /r/HasProperty | coated with a varnish of alum
Facets:
value: for fireproofing
type: PURPOSE
Source sentences:
text: In collaboration with the wallpaper manufacturer Jean-Baptiste Réveillon, Étienne constructed a 37,500-cubic-foot (1,060 m3) envelope of taffeta coated with a varnish of alum for fireproofing.