Historical clue formulations

• Bump on a log — 2019-02-23
• Knotty tree growth — 2018-10-27
• Lump on a trunk — 2018-04-18
• Knotty growth — 2017-12-14
• Small knot — 2012-03-22
• Small knot — 2011-08-10
• Knot — 2010-02-11
• Lump in cloth — 2009-07-17
• Singer Ives — 2007-07-30
• Singer Ives — 2006-06-20
• Small knot — 2005-09-29
• Singer Ives — 1999-06-14
• Knot in wood — 1993-12-22