"He can lift 6200 pounds." Norris remarks. "That's more than that car the publisher gave us. An extremely nice, gentle man." "And a great Christian--they say he signs his letters 'Yours in Christ.'" "Belongs to one of those Southern sects, he comes from Toccoa, Georgia." "I believe he won an Olympic medal..."

"I saw him do it!" Norris says triumphantly.

* Heaviest Human of All Time

Not all questions--however impressive the book's photograph of Robert Earl Hughes. "Heaviest Human of All Time"--are so readily referred to simple ocular evidence. Both McWhirters were unsuccessful Conservative candidates for Parliment in 1964, and Norris is particularly opposed to confiscatory income taxes ("Did I say confiscatory? 106 per cent! That's beyond confiscation!") Did the brothers' social and political background help inform their eloquent list of the perquisites available to U.S. Senators, the highest paid legislators in the world? And in other cases, such influences may have been praiseworthy effects. If a pub debate about "Greatest Mass Killings" turned to the Guinness Book, its participants would learn that a Soviet radio station--source normally unknown to historical scholarship--once accused the Chinese People's Republic of killing 26.3 million people.

In other cases, however, the McWhirters are less friendly toward inflated claims. The pub debaters could learn from Guinness that "Professor Paul Rassinier, a Buchenwald survivor and holder of the Medialle de la Resistance, published evidence in 1964 to the effect that the total Jewish death count could not have exceeded 1,200,000, as opposed to the widely accepted figure of 6,000,000." But they would have to look up Rassinier's Le Veritable Prices Eichmann ou Les Vainqueurs incorrigibles (Paris, 1964) to learn the nature of the evidence--that the World Jewish Congress's pamphlet on the Eichmann trial says 900,000 Jews died at Auschwitz, whereas "certain Jewish 'historians'" say four and a half million Jews were deported there. Since 900,000 is to 4,500,000 as one is to five. Rassinier explains, "it appears very likely that the number of dead can be reduced from six million to one.

Ross concedes that massacres are a difficult case. "People say what's the biggest massacre," he shrugs. "Well, it's an easy question to ask, but a damned difficult one to answer."

*Extremes of Human Longevity

The McWhirters' literary knowledge may be a little shaky, too. "Some authors such as James Joyce eschew punctuation altogether," they remark in the section on "Longest Sentence." And yet their own style has a charm all its own, a stern, Old-World censoriousness of tone that begins with the Guinness Book's first page, a starkly understated discussion of the sizes and careers of various giants, and proceeds through recurring lamentations on the varieties of human duplicity. For example, the McWhirters say. "No single subject is more obscured by vanity, deceit, falsehood and deliberate fraud than the extremes of human longevity." But they insist that even such cascades of synonyms are intended to be purely factual.

"Objectivity of tone?" Ross scoffs. "There's lists and lists of phony centenarians." "Have you ever seen a centenarian?" Norris adds. "I've seen three. They're incredibly frail. You're astonished that they live till breakfast."

And yet, for all their book's implacable esthetics, the brothers retain their faith in human nature. In their conversation, there are none of those Biblical-sounding references to vanity, deceit and deliberate fraud. "Generally speaking." Norris remarked last week, putting down his fork, "when people claim a thing they are telling the truth."

Then it was time for their next interview. As James Joyce once wrote--punctuation or not--"All the guinnesses had met their exodus."