WONDERFUL INVENTIONS: MOTION PICTURES, BROADCASTING, AND RECORDED SOUND AT THE LIBRARY OF CONGRESS, edited by Iris Newsom ($40, including two 12-inch records: Write, Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402; stock No. 030-00109-1).

Although few Americans are aware of it, the Library of Congress contains one of the world’s great archives of broadcast material: films, radio programs, television shows and sound recordings, much of it dating to the turn of the century. This rather mixed bag of essays deals with various elements of the library’s vast holdings.

David Raksin, who arranged the music for “Modern Times” and is best known for the score of “Laura,” provides a vivid and intriguing portrait of Chaplin at work in “Life With Charlie.” Raksin’s work, which includes the scores to “Force of Evil,” “Separate Tables” and “Carrie,” as well as the UPA cartoons, “Giddyap” and “The Unicorn in the Garden,” is discussed in detail in two other articles.

David Shepard’s lively essay, “Authenticating Films,” demonstrates how sloppy research using worn, damaged and incomplete prints has led critics to construct elaborate--and completely erroneous--theories about the work of Sergei Eisenstein and John Ford.

Unfortunately, not all of the essays are so compelling. Ross Care examines the score to Disney’s “Bambi” as if each note were a sacred relic: His overly detailed analysis would tax even Walt’s interest in the film. Paul Spehr’s statistical study of production at Biograph Co. belongs in a technical journal, not a book intended for a general audience. An article on the American Film Institute by Lawrence Kerr reads like a promotional piece for the organization.

A double album of film music, keyed to various articles, accompanies the book. This sensible multimedia approach enriches the discussions, especially the scene-by-scene studies of Raksin’s compositions and the music for “Star Trek.”

“Wonderful Inventions” belongs in the library of anyone interested in gaining a historical perspective on the various means of communication currently lumped together as “The Media.”