Millikan's Reasearch

In 1906, Millikan began experiments at the University of Chicago to attempt to measure individual electron charges, and with much greater accuracy than Thomson and co-workers had been able to achieve with the plum pudding model. Thomson had found that electrons were located outside of the nucleus, but Millikan revised the previous model and found the actual charge of it. One of the great improvements was the use of oil drops instead of the cloud of water drops that Thomson used. In Millikan’s apparatus, the water drops would have quickly evaporated, whereas individual oil drops could be studied for a long time.