The Folger Shakespeare Library on Capitol Hill has begun a major fundraising drive with the goal of expanding its book storage capacity and increasing the size of its reading room. The library plans to add a two-story underground vault for books and almost double the size of the current reading room by adding a room where a terrace is now.

The expansion will not take any additional property on Capitol Hill, where the Folger owns several nearby townhouses. "It was the best solution without pulling down blocks of Capitol Hill," said Dr. James Elder, assistant to the director of the library.

The plan, designed to meet the library's space needs through the year 2010, also is aimed at providing better temperature and humidity control to protect the library's priceless Shakespeare editions, including 70 copies of the 1623 First Folio, and to provide protection from the corrosive effects of Washington's polluted air, Elder said. "The air quality is so drastically different from when the library was built," he said.

The additions will also allow the library to consolidate sstorage of rare books and manuscripts, now disapersed over seven areas.

The fundraising drive, which is also to raise money for renovation and expansion of the library's endowment, has a goal of $9.7 million, with the building changes and additions expected to cost about $4.7 million.

Since 1932, the collections have quadrupled and the use of the collections has grown from 2,300 reader days in 1953, to more than 10,000 in 1976.

Because of the nature of the collecion, the library, which was established in 1932, is open only to advanced graduate students snd other scholars and those with a specialized need to use the library's manuscripts, said Elder. Besides the Shakespeare collection, the library also houses one of the largest collection of English Renaissance matericals outside Great Britain.

"We have entrusted to us one of the most precious treasures in the world," Elder said.