1. Stethoscope   Karl Benz   Evangelista Torricelli   Dr. William Stokes, Rene Laennec   Alessandro Volta   Hint Half-n-half Clue   2. Jet Engine   Sir Frank Whittle   John J. Loud   Dr. Wallace H. Carothers   Otto von Guericke   Half-n-half Clue   3. Shorthand   Edward Jenner   David Bushnell   Louis Pasteur   Sir Isaac Pitman   Half-n-half Clue   4. Microscope   Gottlieb Daimler   C. F. Brush   Z. Janssen   Edmund Cartwright   Half-n-half Clue   5. Electric Battery   Kirkpatrick Macmillan   Edmund Cartwright   Alessandro Volta   Leo H Baekeland   Half-n-half Clue   6. Printing Press   H. W. Seeley   Dr. William Stokes, Rene Laennec   Sir Isaac Pitman   Johann Gutenberg   Half-n-half Clue   7. Gunpowder   Alessandro Volta   Edmund Cartwright   Roger Bacon   Bardeen, Shockley, Brattain   Half-n-half Clue