The 178th commencement at Colby College in Waterville will begin at 10 a.m. on Sunday, May 23, on the lawn of Miller Library. George J. Mitchell, former majority leader of the U.S. Senate, peace broker for Northern Ireland and Presidential Medal of Freedom honoree, will address more than 500 members of Colby's Class of 1999, their families, the faculty and guests. The public is welcome at the outdoor graduation, but tickets will be required if weather requires moving the program to the Alfond Athletic Center.

William R. Polkinghorn of Santa Monica, Calif., this yearšs valedictorian and class marshal, will lead the procession of seniors. A religious studies and chemistry double-major, he had a 4.17 cumulative grade-point average prior to the awarding of grades for the final semester. Polkinghorn, a Rhodes Scholar, is a member of Phi Beta Kappa.

Ezra Dyer of Beverly, Mass., was elected by his classmates to address the convocation as the senior class speaker. A graduate of Lincoln Academy in Newcastle, Maine, Dyer is an English major and the opinions editor and columnist for The Colby Echo.

Mitchell, a Waterville native, worked on Colby's summer grounds crews before attending Bowdoin College. His father, George Mitchell, Sr., was a custodian at Colby and his brother John "Swisher" Mitchell was a long-time basketball coach at the college.

Mitchell received an honorary doctor of laws degree from Colby in 1983. At commencement honorary degrees will be presented to Judy Woodruff, CNN's prime anchor and senior correspondent; Al Hunt, the executive Washington editor of The Wall Street Journal and a Capital Gang panelist on CNN; outgoing chair of Colby's Board of Trustees Larry Pugh '56 and his wife, Jean (Van Curan) Pugh '55; Mainešs independent governor Angus King; and genetic cancer-research pioneer Patricia (Davis) Murphy '68.