https://youtu.be/EmcflrK2GAk
https://m.youtube.com/watch?v=7RGBA6a76JE
https://m.youtube.com/watch?v=D28EckuwzQU
https://m.youtube.com/watch?v=df669EBqgTY
https://youtu.be/2i-L74Vwe6g
1894- the pneumatic hammer is patented by American, Charles King.
https://youtu.be/v9l8Rl2iRuA
https://youtu.be/quWFPfF95Yg
https://youtu.be/Yfc6gRjPRrg
https://youtu.be/maIDknW4DME