Galileo, Galileo he was a important person in history, and played a good roll on history. Galileo Discovered Ganymede, Callisto and the Io moon. Which is cool that he could do that with the telescope, which goes to show that the telescope has and will have a good impact on history.

The Slide Rule is a super duper great invention this thing was great think about it this is kind of like that calculore and it is like that it is kinda self explanatory you have to slide it to work so ya. It helps you do math problems.