Albert Carnesale, who has worn two hats for several months, has now put on a third: Acting President of Harvard University.

The announcement yesterday that President Neil I. Rudenstine is taking a medical leave of absence has rendered Carnesale, also Dean of the Kennedy School and Provost, the most important figure of the central administration.

Carnesale's somewhat bumpy ride from JFK Street to Massachusetts Hall began last spring. Within a day after the announcement in April that Jerry R. Green would step down as the University's provost, Carnesale's name was on some people's lips as a likely successor.

The personable, seasoned dean of the Kennedy School seemed the perfect replacement for Green, who had come from outside the central administrative structure.

Carnesale was also the savior of the Kennedy School, the dean who brought together a faculty fractured by years of mushrooming growth and lacking of a clear mission. He was a Harvard insider, a successful fund raiser and a tested supporter of Rudenstine's goal of unifying Harvard's schools.

To no one's surprise, Carnesale was made provost, and since July 1, he has been living a dual life as both dean of Harvard's school of government and the University's second-in-command.

"To some extent I'm facing not so much the limitations of there being 24 hours in a day--we all face that--but rather I'm running up against [the fact] that you can't be in two places at the same time," he said in September.

Despite the load, however, Carnesale seemed to hold on to his sense of humor. His provost's desk had three boxes: "In," "Out" and "Too Hard."

So far, it seems that few things have been "too hard" for the administrator.

"You notice my 'Too Hard' box almost never has anything in it," he joked.

And despite the triple role that his new responsibility implies, Carnesale said yesterday that he will not be overwhelmed by the pressure of serving simultaneously as acting president of the university, dean of the Kennedy School and University provost.

Carnesale Himself

The 57-year-old former engineer is a pleasant, slightly self-deprecating man with some resemblance to a healthier-looking Sen. Edward M. Kennedy '54-'56 (D-Mass.).

His hobbies include opera, fishing, reading and "walking along the Charles for a few miles a day, dressed even worse than usual."

Recently separated from his wife Janet, he has two children: Keith, an assistant solicitor in Georgia, and Kimberly, who graduated from the College in 1992 and now is a student at the Harvard Business School.