Out of Patagonia IN 1905, A.F. Tschieffely, one of the great horsemen of his time, set off on a 10,000-mile ride, alone with two horses, from his home in Buenos Aires to Washington, D.C. The trip took 2 1/2 years, crossing the Andes and the jungles of Central America. The purpose of the trip was not to prove the rider's abilities, but those of ordinary Argentinian working horses.

The rider recorded his epic journey in Tschiffely's Ride (Simon & Schuster, 1933). Tschiffely rode through thousands of miles of wilderness, just before it was fenced off and paved over and cut down, and he describes the whole experience in simple unaffected prose. His focus is on the horses, but we are struck by the enormous hardships he himself endured, including injuries and malaria. We are struck, too, by his superb knowledge of horses and most of all by his obvious devotion to his companions, Mancha, a paint, and Gato, a buckskin.

Tschiffely was received by President Coolidge. Mancha and Gato went back to Argentina by ship, where they were retired as national heroes to a ranch near their birthplace. Tschiffely wrote several other books, notably a biography of British socialist and adventurer R.B. Cunninghame Graham and This Way Southward, a travel book about Patagonia and Tierra del Fuego. He died in 1954. A paperback edition of Tschiffely's Ride, titled Southern Cross to Pole Star, was issued by J.P. Tarcher in 1963 but is out of print. STUART BYCZYNSKI Silver Spring The Gulf Crisis I WAS struck by the absence of any book specifically about Iraq -- the architect of the region's troubles -- in Thomas W. Lippman's list of recommended readings on the Persian Gulf (Book World, Aug. 12). This omission is easily rectified by including Iraq: Eastern Flank of the Arab World by Christine Moss Helms (Brookings Insitution, 1984). This study, although written in typical dry-as-dust Brookings prose, succinctly and skillfully describes Saddam Hussein's authoritarian regime and his view of himself as the rightful successor to Egypt's Nasser as a pan-Arab leader. Helms also makes clear that Saddam is driven not just by personal ambition but by a radical political philosophy -- Baath socialism -- which advocates not only the unity of the Arab world, but also the destruction of one non-Arab state (Israel) and the dismemberment of two others (Turkey and Iran). Written at the height of the Gulf War between Iraq and Iran, the book ably demonstrates that Saddam did not become the "beast of Baghdad" overnight. The Helms work remains in print and is also probably available in any large library. DAVID F. RUDGERS Arlington The Arlens, pe`re et fils IF PEOPLE today think of Michael Arlen at all, they probably recall the father poignantly described by Michael Arlen Jr. in Exiles, or associate the name with the Jazz Age Mayfair seen on TV's "Mystery." But Michael Arlen Sr., born Dickran Kouyoumdjian, was one of the most shatteringly accurate observers of the vagaries of the human heart ever to write in English. And what English! No short quotation can give its flavor, that of a mosaic of phrases which, like Schubert Lieder, seem to form an alphabet to spell out every possible nuance of human feeling.

Arlen's novels and short stories are not empty chronicles of the vapidities of the Bright Young Things. They will astonish and transfix the readers of the '80s who looked into the mirror of The Bonfire of the Vanities. And Arlen's masterpiece and best-known novel, The Green Hat (1924), is a story of the innocence of modern sensibility that seems even more true than when it was written. Any good library will have copies of the stories and novels. L.S.B. MACCOULL Washington Justice for All "INNOCENT MEN are never convicted," a prosecuting attorney boasted. Yale law professor Edwin M. Borchard responded by writing Convicting the Innocent: Errors of Criminal Justice (1932, Yale University Press). With some help from Felix Frankfurter and others, Borchard collected 65 documented accounts of innocent men and women who had been convicted of crimes, imprisoned and later exonerated. He included six cases in which, after the defendant had been sentenced on a murder conviction, the "murdered" victim turned up alive and well.

A quarter of a century later, Judge Jerome Frank collaborated with his daughter, journalist Barbara Frank, in the writing of Not Guilty (1957, Doubleday; 1962, Popular Library). Barbara Frank collected, from 15 states and the District of Columbia, the stories of 36 defendants who had been wrongfully convicted. Her father used the cases as starting points for essays that explored the causes of mistaken guilty verdicts. Judge Frank concluded that "erroneous identification of the accused constitutes the major cause of the known wrong convictions."

Both Convicting the Innocent and Not Guilty (library editions of both are available from Da Capo) offer the reader a fascinating parade of stories, incredible but true, and a powerful call for criminal law reform. The reader will discover that much of the books' message applies to today's criminal justice system. MICHAEL R. MALLOY Ellicott City, Md.

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