He had just enough money to get in Trinity but not all the expenses were paid like books and food. He had to pay his way by doing chores and waiting on people at the dinning table. He kept journals of all of his experiences. He wrote about how he was inspired by famous people like Aristotle, Galileo, and Rene Descartes. It was all kept in his notebooks. During this time, the Bubonic Plague was in full affect. Isaac had to go back to the farm in Woolsthrope and wait till to The Plague was over. He got occasional visits to go to Trinity, but only two visits were made during this time period, which ended in 1667; about two years out of school. During The Plague Isaac did his finest works and made tremendous discoveries. Since he studied famous scientists, he continued to pursue their work. He made experiments to test his thoughts with other scientist's thoughts. One of his inventions was fluxion method. It was a mathematics technique that branched off into what is now known as calculus. He made it easier to calculate lines and curve in more inverse operations. This technique is still used today. The only thing that wasn't done was publicizing his methods; which could hurt him in the future. Next he experimented with light, prisms, and lenses. He wanted to find a way to make a better telescope. In this process he wrote this quote: " Light consists of Rays differently refrangible, which were accordingly to their degrees of refrangibility, transmitted towards divers parts of the wall. What is more, I have often with Admiration beheld that all the Colors of the Prism being made to converge, and thereby to be again mixed, reproduced light, intirely and perfectly white." This was said when he discovered that Violet light bends (refracts) more than indigo, which refracted more than blue, and so on. Later he returned to Trinity College in 1667. While in College he worked with light for a while longer never making public of his discoveries.