The multiple interview approach to most subjects short of Watergate is risky, and John Grierson--pioneer documentary filmmaker and publicist--proves no exception. Scattering biographical data among 50-odd dialogues with Grierson cohorts and acolytes, and inserting samples of Grierson's own speeches and writings, James Beveridge--himself a Grierson disciple--has knotted together a book without sinew. What we get are impressions--filmmaker Roberto Rossellini insisting that Grierson taught him ""how to look at the truth,"" historian Lewis Jacobs identifying him as ""salesman par excellence""--which add up to a lengthy but far from exhaustive probing of man and career. The question-and-answer interviews ramble and lose direction: a pity, because Grierson's are the sort of accomplishments that want only a chronicler with the patience to sift. While admitting him to be ""not very widely known beyond a fairly limited circle,"" Beveridge presumes general interest in both Grierson and his acquaintances, according each interviewee--from his Scottish high school teacher to film archivist Henri Langlois--more than adequate attention. Preceding an exchange with film critic Bosley Crowther, for instance, is not only an introduction to Crowther but also a paragraph on the ambience of their Times Square meeting. If one has the patience to dredge, the book is not without felicities--in particular Grierson's own prose, much of which also appears in Forsyth Hardy's Grierson On Documentary--but with no focusing intelligence and such a mass of extraneous fact and opinion, it is likely to find few friends beyond that ""fairly limited circle"" Beveridge identifies.