Newton continued to experiment in his laboratory. This mix of theory and practice led him to many different kinds of discoveries.
His theory of optics made him reconsider the design of the telescope, which up until this point was a large, cumbersome instrument. By using mirrors instead of lenses, Newton was able to create a more powerful instrument, 10 times smaller than traditional telescopes. When the Royal Society heard about Newton’s telescope they were impressed. This gave Newton the courage to tell them what he described as a ‘crucial experiment’ about light and colours.