but in time others began grinding smooth pieces of glass into convex lenses and producing proper eyeglasses.
The art of grinding eyeglasses was known almost 600 years ago. A couple of hundred years later, the children of a certain eyeglass grinder, while playing with lenses, placed one in front of another and found that they could see better through two lenses than through one. They informed their father about this curious occurrence, and he began producing tubes with two magnifying lenses and selling them as a toy. Galileo, the great Italian scientist, on learning of this toy, used it for a different purpose and built the first telescope.
This example, too, shows us that observation leads man by the hand to inventions. This example again demonstrates the truth of gradualness in the development of inventions, but above all also the fact that education amplifies man’s inventiveness. A simple lens-grinder formed two magnifying glasses into a toy – while Galileo, one of the most learned men of his time, made a telescope. As Galileo’s mind was superior to the craftsman’s mind, so the invention of the telescope was superior to the invention of the toy.
In the second, most consequential part of our lecture, we learned about two things. First, that discoveries and inventions do not fall to earth from out of nowhere but are the results of human effort. The impulse behind the effort is needs, and the path to new discoveries and inventions is indicated to us by observation – by the attentive examination of what is happening around us. However, a person who wants to do something new should not only observe: he should learn, that is, get knowledge of what other people have done,
