It is some years (1959) since Thurber's fond commemorative of The Years with Ross. Now in time for the 50th anniversary of the New Yorker, Brendan Gill, its resident theater critic, ""Talk of the Town"" man, and sometime short-story writer, has written this casual portrait of the institution which through the years with Ross and then William Shawn has been committed to the wit and seriousness, integrity and purity of its publication. Blithe and gregarious by nature, Gill is a raconteur of consummate amiability which means that his book is a source of marvelous gossip -- gossip which we know is ""more interesting than any other form of speech."" (Ogden Nash, who else?) But Gill is never guilty of hagiography; here and there he cuffs the dinginess of the facility, which produces such an elegant product; or the sometimes outright incivility (usually on that slow morningafter walk to the watercooler) of his confreres, particularly during that earlier era of White, Benchiey, Perelman, Parker, etc.; or some of the less charitable impulses of great talents with lesser hearts (Thurber's atavistic malice; Edmund Wilson's constitutional diffidence; Pauline Kael's holy terrorism). One by one you'll meet Wolcott Gibbs and Peter Arno, Steinberg and Steig, Lois Long and Charles Addams, John O'Hara -- ""the best of us"" -- and all the men and women of manifold taste and talent who have been contributing to the New Yorker's perfectionist aims and achievements. Presiding over them all was of course Ross, that bigoted, irascible ""water buffalo"" (these earlier words are gentled in an envoi) and his successor Shawn. so unlike him. but equally dedicated -- to the exclusion of all other interests -- and reticent to the point of anonymity. Early on, Gill says he has hoped to give this book (prodigally illustrated by the way) a ""weight and shape no greater than that of a cloud of blue butterflies."" Just as surely they take wing.