411 REFERENCE · Wiktionary
Hilt's law
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Etymology
Observed by professor Carl Hilt (1873).
Proper noun
en geology A geological law stating that the deeper coal is found, the higher its rank (carbon content). It holds true when the thermal gradient is entirely vertical.
en eponyms