Historical clue formulations

• Temper — 2024-09-14
• Make malleable using heat — 2024-05-05
• Heat, as to soften metal — 2017-10-01
• Temper, as metal — 2017-08-30
• Strengthen — 2014-04-13
• Temper, as metal — 2010-08-05
• Temper, as metal — 2007-11-08
• Toughen, as glass — 2005-10-04
• Temper, as metal — 2002-04-03
• Strengthen — 1999-09-05
• Temper, as metal — 1997-09-01
• Temper, as steel — 1995-10-30
• Temper, as glass — 1995-04-03
• Treat, as glass — 1994-12-25
• Temper — 1994-04-07