In response, the undergraduate Interfraternity Council passed a resolution condemning discrimination. In the 1960s, the Trustees established a Commission to examine the membership restrictions of those national organizations. Cornell adopted a policy that required fraternities and sororities affiliated with nationals that discriminated based on religion or race to either amend their national charters or quit the national organizations. As a result, a number of national Greek organizations dropped racial or religious barriers to their membership. In 1873, the cornerstone of Sage Hall was laid. This new hall was to house the Sage College for Women and thus to concretely establish Cornell University's coeducational status. Ezra Cornell wrote a letter for posterity—dated May 15, 1873—and sealed it into the cornerstone. No copies of the letter were made, and Cornell kept its contents a secret. However, he hinted at the theme of the letter during his speech at the dedication of Sage Hall, stating that "the letter deposited in the cornerstone addressed to the future man and woman, of which I have kept no copy, will relate to future generations the cause of the failure of this experiment, if it ever does fail, as I trust in God it never will." Cornell historians largely assumed that the "experiment" to which Cornell referred was that of coeducation, given that Sage Hall was to be a women's dormitory and that coeducation was still a controversial issue at the time. However, when the letter was finally unearthed in 1997, its focus was revealed to be the university's nonsectarian status—a principle which had invited equal controversy in the 19th century, given that most universities of the time had specific religious affiliations. Cornell wrote:  Between 1872 and 1875, the university's first professor of physics William Arnold Anthony and student George S Moler (later, a professor at Cornell) installed two electric arc lamps on campus, one of which was in the Sage Chapel tower. The set-up represented many firsts, the first dynamo and outdoor electric lighting in the United States, and the world's first underground electricity distribution system. It was said to be the "first locality in America, if not the world, to have a permanent installation of electric arc lamps." The lamps were "visible for many miles around, and it excited the wonder of the inhabitants." In 1883, Cornell was one of the first university campuses to use electricity to light the grounds from a water-powered dynamo. In 1904, a hydroelectric plant was built in the Fall Creek gorge.