1. Who invented Machine Gun ?

Answer:

Helge Palmcrantz, Swedish inventor and industrialist

2. Who invented Steam Engine (Piston)

Answer: Thomas Newcomen of Britain in 1712

3. Who invented Stethoscope ?

Answer: Laennec of French in 1819.

4. Who invented Gramophone ?

Answer:

Emile Berliner in 1887.

5. Who invented Circulation of blood ?

Answer: William Harvey of Britain in 1628

6. Who invented Open Heart Surgery ?

Answer:

Dr. Daniel Hale Williams

7. Who invented Floppy disk ?

Answer: IBM in 1970