Erasmus Smith's Professor of Natural and Experimental Philosophy at Trinity College Dublin is a chair in physics founded in 1724 and funded by the Erasmus Smith Trust, which was established by Erasmus Smith, a wealthy London merchant, who lived from 1611 to 1691. It is one of the oldest dedicated chairs of physics in Britain and Ireland. Originally, the holder was to be elected from the members of the college by an examination to determine the person best qualified for the professorship. Since 1851, the professorship has been supported by Trinity College. Of the 22 holders of this chair, seven were Fellows of the Royal Society while one, Ernest Walton, won the Nobel Prize for Physics.