This weekend's Independence Day festivities in Washington, DC, when the National Mall is jammed for the traditional concert and fireworks extravaganza, is a boom time for flag dealers, refreshment stands and souvenir vendors. And it's Anthony Pitch's favorite time of year. He writes and sells a little paperback book that's a hit with Washington tourists. It's called-Exclusively Presidential Trivia, and it contains more than 650 brain-teasing questions and answers about U.S. chief executives. Anthony pitch has written scholarly books on subjects like the burning of Washington by British troops in 1814. And he's finishing another serious book about the assassination of President Abraham Lincoln. But Mr. pitch, a native Englishman and former journalist in Africa and the United States, also publishes simpler tourist guidebooks and maps, leads tours of Washington and each year freshens his Exclusively Presidential Trivia book. Anthony Pitch says such trivia as the reason Herbert Hoover was left out of a 1938 series of U.S. postage stamps about former presidents seems, well, trivial- even worthless. But he says these little nuggets are popular with families this Independence Day weekend. They challenge the memory of older folks and can provoke an interest in history by children. Followings are talks between Pitch and Landphair, a radio programme host. Pitch:' I'm a voracious reader of subjects that fascinate me. The presidency fascinates me. History fascinates me. And so even when I'm doing my very serious research, I am able to extract from my deep research gems that I can put in later editions of the book.' Landphair:' All right, I'm going to give two or three examples. And I'm going to ask you to pause just a second before answering to give our listeners a chance to perhaps take a guess. Here's the first one: Now we mentioned Herbert Hoover earlier. He was the thirty-first president of the United States. He served in the late 1920s and early 1930s. He was born in the state of Iowa. And you ask in the book, 'Why is that significant?'' Pitch: 'Because Hoover was the first president born west of the Mississippi River. That's why I find trivia fascinating, because from that little question and answer, you can now enlarge it into a perspective of how long it took for a president to arise from that far west.' Landphair:' Let's try another one. How many U.S. state capitals are named after presidents? And by the way, before you answer, I asked a colleague this question, and she guessed 40. It's not 40, is it?' Pitch: 'No, it isn't. The four cities that are state capitals named after presidents are Jefferson City, Missouri Lincoln, Nebraska Madison, Wisconsin and Jackson, Mississippi.' Landphair: 'Just four, and these are early presidents. We don't have any' Clintons' or' Bushes' yet.' Pitch:'Not yet, but there's such a strong movement afoot amongst partisan Republicans to name places after Ronald Reagan that you should get ready for a[Reagan] state capital.' Landphair: 'Have you come up with any questions yet about President Bush?' Pitch: 'Yes. In the latest edition, I ask what his nickname was when he was at Phillips Academy in Andover, Massachusetts. It's a very posh [exclusive] school. And he was nicknamed' Lip, ' because he wasn't afraid to voice his opinions on any subject!' Anthony Pitch publishes three other trivia books besides the one called Exclusively Presidential Trivia. The others are about the White House, America's first ladies, and Washington, DC. Mr. Pitch's webpage is dcsightseeing com. By the way, if you're wondering about the answer to the first trivia item about President Hoover: He was left out of the series of stamps about ex-presidents in 1938, not because many people still blamed him for prolonging the Great Depression, but because the Postal Service had a strict role that no living person, not even a president, could appear on a U.S. po