1. Who invented Safety Pin ?

Answer: Walter Hunt of U.S.A. in 1849

2. Who invented Steam Engine (Condenser)

Answer: James Watt of Britain in 1765

3. Who invented Stethoscope ?

Answer: Laennec of French in 1819.

4. Who invented Vitamin D ?

Answer:

Edward Mellanby discovered Vitamin D while researching a disease called rickets in 1922

5. Who invented X-ray ?

Answer: W.K. Roentgen of Germany in 1895.

6. Who invented Steam Engine (Piston)

Answer: Thomas Newcomen of Britain in 1712

7. Who invented Bicyle ?

Answer: Kirkpatrick Macmillan of Britain.