You have a map, and five icons below corresponding to inventions; the purpose of the exercise is to position the inventions where they took place. Click on an icon and drag it so that it coincides with the square under the place where (you believe) it belongs, and release the mouse. If you have guessed right, the icon will stay; if you are wrong, it will return to its original position below the map, drag it again to another position. Repeat for each icon.