NOW THAT a well-known book club is offering the Oxford English Dictionary as a come-on offer to prospective members, many people take it without realizing what will soon appear on their doorsteps - the rationable being that at a list price of $75 it must be extraordinarily good dictionary. And extraordinary it is; for it is the most comprehensive English dictionary based on historical principles ever published, with quotations illustrating the history of usage from the 11th century to the end of the 19th. The master planner, the guiding light and editor of this extraordinary work, was James Murray - a basically self-educated Scotsman who became one of England's greatest lexicographers.

His granddaughter, K. M. Elisabeth Murray, has written a biography of this remarkable man which not only sheds light on the history and difficulties of the dictionary itself but also gives a glimpse into the small world of Victorian literary and linguistic schoolarship.

Murray's parents were Scottish tradesmen, but by the time he was 17 his local grammar school education had helped him become assistant schoolmaster at Hawick grammar school. At 20 he was a master at the Subscription Academy in Hawick. With the illness of his first wife, Murray moved to the better climate of the south to take a job in the London office of the Chartered Bank of India. The budding philologist was introduced to the London Philological Society where his talents were quickly recognized. With the death of his first wife and remarriage to Ada Agnes (by whom he had 11 children), he moved to Mill Hill where he was once again a schoolmaster. And during all of this time he was publishing, editing for the Early English Text Society, lecturing and leaning.

It was in 1879 while at Mill Hill that Murray became editor of the new dictionary, a project of the Philological Society. In the early years, besides teaching full-time, he spent long, hard hours in the corrugated iron building, jokingly called the Scriptorium, which he had built behind his house to store the thousands os slips of paper coming from readers throughout England and America. He wrestled with the problems of the dictionary and with the problems of finding competent staff, good research materials - many of which he bought with his own money - and of simply not having enough money for himself and the work.

When he moved to Oxford in 1885 to work full-time on the dictionary, his difficulties increased. He had to contend with mounting pressure from his board of publishers at Oxford University Press and from a few learned colleagues to hurry the work, to compromise his principles, cut the sixe of the dictionary down in order to meet deadlines and to keep costs down.

What comes through most clearly in this biography is the integrity of the man and scholar. THe Scotsman Murray - self-disciplined, strict but not rigid or humorless - refused to take shortcuts. The work, although it progressed slowly, was done with the thoroughness, intelligence and knowledge which had so distinguished him among his colleagues in the Philological Society. So what was to be six to seven thousand pages long and completed in ten years expanded until the dictionary became the history of most English words from the 11th century until the present - alas that Victorian prejudice ruled out the vulgar words.

When the 12th and last volumne of the O.E.D. was pushlished in 1928, 13 years after Murray's death, there were 15,487 pages covering some 250,000 English words. And the quiet, dedicated scholar Murray had carefully done almost half of the work himself - A-D, H-K, O, P, and T.

His granddaughter's biography shows that Murray was not the "humble drudge" which Dr. Johnson lamented was the public characterization of the lexicographer, even though his life became the dictionary and finally was the dictionary. As his colleague and later co-editor, Henery Bradley, declared in a dinner speach, it might have been "a national calamity" if someone other than Murray had been chosen to do the job that he had done so well and so conscientiously.

For all that, all English speakers owe him a debt of gratitude.