That's a thumb hitting hammer. Come in a wide variety of patterns.

Mick Dowling
Melbourne Australia

------ Original Message ------
From: "Ed O'" 
To: OldTools@s...
Sent: Tuesday, 18 Jun, 2019 At 5:19 AM
Subject: [OldTools] Help with identifying a hammer

I picked up a hammer like tool a couple of weeks ago and cannot find it 
in "The Hammer - The King of Tools" book by Ron Baird and am unsure what 
it is for, anybody know?