Floating 'think tank' -- 1899 style; Looking Far North: The Harriman Expedition to Alaska, 1899, by William H. Goetzmann and Kay Sloan. New York: The Viking Press. 272 pp. $17.95.

In the last few years of the 19th century, Edward H. Harriman (father of Averell) rose among the board-room barons to gain control of the Union Pacific Railroad. Perhaps in celebration of his newly won power and enormous wealth, Harriman refitted an entire steamship into what he liked to call a ''floating university.''

Harriman provided the ship and crew, and he charged C. Hart Merriam, head of the Biological Survey of the US Department of Agriculture, to select a staff of eminent research scientists and naturalists who would agree to go along with a short notice.

The staff list reads like a collegiate Noah's ark: two geologists, two ornithologists, etc., plus two artists and two nature writers - the sentimental John Burroughs and a difficult California Scot named John Muir.

Most of this ''floating think tank'' had to be brought from the East to Seattle, where Harriman's vessel, George W. Elder, lay at dock. With true magnate aplomb, the railroad baron provided a train of Pullman ''palace cars'' to haul this brain trust across North America. With so many commanding minds on board, the trip across the continent must have seemed like an interminable faculty meeting on wheels.

Harriman's ship steamed out of Seattle at the end of May 1899, and for two months cruised the coast of British Columbia and Alaska. The able Captain Doran took the research-and-pleasure vessel in and out of coastal and Aleutian islands , north to the Bering Strait and west to the coast of Siberia. The Elder made many reconnaissance stops for the scientists to collect specimens and data, and many hunting stops, for Edward Harriman, in typical Victorian style, was determined to bag a giant Alaska brown bear.

The motives behind the railroad baron's scientific grand tour are interesting and complex. For a self-made man of limited formal education, it must have been quite a shot-in-the-ego to be the patron of America's scientific elite. Harriman may also have dreamed, after gaining control over such a major share of the country's railroads, of masterminding a railroad under the Bering Strait to connect North America with Asia and eventually with Europe. It was an age when engineering and private capital seemed to make anything possible.

Edward Harriman's only trophy bear was a small female and her cub. Scientifically the expedition was little more than a coastal reconnaissance. Yet the scientific papers it engendered continued to be published, at Harriman's expense, for more than 12 years. The expedition's grand style alerted the public to the fact that ''Seward's ice box'' was vast and interesting territory indeed.

The author's prose often manages to convey some of the excitement of the expedition. The appendices are fun, and the photographs of Edward S. Curtis are an added bonus. The Harriman expedition is too limited a subject to land Kay Sloan a Parkman Prize, or William H. Goetzmann another Pulitzer, yet they have given us a thoughtful book on an episode in our history which deserves refined attention.