Sounding and interacting with the Hegar sounding rod

• 00:00
• 00:42
• 01:11
• 01:54
• 02:22
• 03:05
• 03:34
• 04:17
• 04:45
• 05:28
• 05:57
• 06:39
• 07:08
• 07:51
• 08:19
• 09:02
• 09:31
• 10:14
• 10:42
• 11:25

Sounding deeply and strongly with a14 mm Hegar sounding rod.