Historical clue formulations

• Bass organs — 2024-12-26
• Breathers? — 2019-01-09
• Half-cup measures — 2016-05-27
• Bass organs — 2015-12-06
• Underwater breathing aids — 2012-03-04
• Breathing aids — 2011-07-03
• Breathers? — 2003-08-26
• Oxygenators — 1994-02-25