Read this: Yale expanded gradually, establishing the Yale School of Medicine (1810), Yale Divinity School (1822), Yale Law School (1843), Yale Graduate School of Arts and Sciences (1847), the Sheffield Scientific School (1847), and the Yale School of Fine Arts (1869). In 1887, as the college continued to grow under the presidency of Timothy Dwight V, Yale College was renamed Yale University. The university would later add the Yale School of Music (1894), the Yale School of Forestry & Environmental Studies (founded by Gifford Pinchot in 1900), the Yale School of Public Health (1915), the Yale School of Nursing (1923), the Yale School of Drama (1955), the Yale Physician Associate Program (1973), and the Yale School of Management (1976). It would also reorganize its relationship with the Sheffield Scientific School.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): When was the Sheffield Scientific School closed?
unanswerable