1. Stethoscope   John Napier   Evangelista Torricelli   Dr. William Stokes, Rene Laennec   Dr. Wallace H. Carothers   Hint Half-n-half Clue   2. Refrigerator   James Harrison, Alexander Catlin   Dr. Alan M. Turing   Evangelista Torricelli   Karl Benz   Half-n-half Clue   3. Submarine   David Bushnell   H. W. Seeley   Gottlieb Daimler   Dr. Alan M. Turing   Half-n-half Clue   4. Air Pump   Andre-Marie Ampere   Bardeen, Shockley, Brattain   Otto von Guericke   Johann Gutenberg   Half-n-half Clue   5. Transistor   C. F. Brush   Bardeen, Shockley, Brattain   James Harrison, Alexander Catlin   Louis Pasteur   Half-n-half Clue   6. Microscope   Gottlieb Daimler   Dr. Alan M. Turing   John Napier   Z. Janssen   Half-n-half Clue   7. Vaccination   Leo H Baekeland   Gottlieb Daimler   Edward Jenner   Nikola Tesla   Half-n-half Clue