Some were lost in thought and books, others in time. In the main reading room of the Library of Congress, the afternoon's collection of scholars, researchers and amateur wisdom-seekers sat at the circular desks that are part of the world's largest library. More than 80 million items are here on 535 miles of shelves. At a rate of one minute per item, eight hours a day for five days a week, 648 years would be needed to examine all that the library holds.

The citizens in the reading room were trying to reach "the instant of knowing," a phrase that Josephine Jacobsen, a former consultant in poetry to the library, used in her farewell lecture in 1973. The citizens had better hurry. Effective March 9, reading rooms will close at 5:30 p.m. every day except Wednesday. The hour for closing has been 9:30 p.m. Reading room hours will drop from 771/2 hours to 541/2 hours a week. All buildings and services will be closed on Sundays.

No assault like this has happened since the library's first day in 1897, when gas lights brightened the reading room. The coming year's budget cuts -- from both the new Gramm-Rudman- Hollings law and earlier reductions imposed by Congress -- total $18.3 million. All sanctuaries within this unique temple of knowledge are to be profaned: funds for buying books, periodicals, microfilms, maps and recordings are to be reduced by 13 percent. About 300 staff members are being dropped from a work force of 5,200.

Next to book-burning, no worse desecration of the Library of Congress can be imagined. Going dark at 5:30 symbolizes a dimming of the nation's intellectual lights. College students who need evening hours are shut out. Working people with 9-to-5 jobs are barred. For the fifth year, the Reagan administration is recommending elimination of the federal library grant programs. Last year they totaled $125 million. In their 1984 platform, Republicans pledged to "wipe out" illiteracy. Instead they are wiping out libraries.

The foolishness and fiscal waste of the assault emerges graphically in the story of Christopher Murphy of the Library of Congress. He is one of 70 staff workers losing jobs in the research services department. With a salary of $37,000, Murphy has had sole responsibility for the past eight months for more than 40,000 books in the Turkish, Turkic and Armenian collections.

A year ago, the library thought the job was important enough to recruit nationally. Murphy, 35, married with one child, was a Near East specialist at the library of the University of Washington in Seattle. His position was tenured. Twenty-eight applied for the Library of Congress job, with four selected as qualified finalists. Murphy, a former Fulbright scholar who studied at the University of Istanbul and earned a doctorate in Turkic languages and literature from the University of Washington, was selected. After transplanting himself and his family from Seattle -- and with the federal government paying the Mayflower moving company approximately $15,000 to transport his belongings cross country -- Murphy went to work at the library in June 1985. Six months later, after being awarded a positive evaluation, he was recommended for retention as a permanent employee. Two weeks ago, his superiors told him that no money was available for his job.

Murphy, who understands budgets, is not upset at anyone at the library. He has questions for those outside the library who, either from ignorance or lack of interest, devalue the kind of work he has committed his professional life to. "I'm happy that I came here," Murphy says. "I enjoyed the work and I performed well. The Turkish collection began with a gift from the Ottoman government in the late 1800s. It has been built up from those several hundred books into a major collection, one of the three largest in the United States. Millions of dollars have been invested in the program. Collections must be closely maintained; otherwise they run the risk of physical deterioration. Qualitatively, larger and larger gaps will appear in the collection."

A library official, as disheartened as Murphy about his departure, says that another employee will have the collection added to his duties. It won't be the same, as anyone can figure out. The books and services to which Murphy now devotes full-time attention will be receiving at best only part-time attention. In addition, no one on the current Library staff has Murphy's knowledge or qualifications.

The loss of this specialist will be severe. Every other employee to be dropped, as well as every visitor and user denied access, has similar stories of deprivation. A government can trifle with many national assets, but the undermining of knowledge and the search for it is a violation of a nation's only enduring strength, access to ideas. Close the doors of a library and you close the eyes of the public. Instead of flying high, we fly blind.