IN ADDITION to an internatinal atlas, a globe is also indispensable for understanding the relations of countries and continents. For example, only a globe is useful in trying to explain that a flight from New York to Sao Paulo spends half its time in the air over Brazil. I recommend the Replogle Land and Sea globe, which is 12 inches in diameter and costs about $20, although there are many others, in all sizes, some with stands and lights inside.

The Times Atlas of World History, (Hammond, $70) explains the rise and fall of empires and nations. The New Cambridge Modern History Atlas (Volume XIV; Cambridge, $65; paperback, $19.95) is unsurpassed in showing the development of Europe since the Renaissance. It has maps showing the battles of Napoleon, what the continent looked like after a major war or treaty, street maps of Paris in 1789, and such detail as a series on the Schleswig-Holstein question.

For spies, guerrillas, counter-insurgents and unusually serious armchair geographers, the Government Printing Office publishes a country-by-country series of maps prepared by the Central Intelligence Agency. I do not find the detail of these charts equal to that of the London Times Atlas, but each comes in a separate envelope, which is handy for the traveler who does not mind being abroad with a map stamped by the CIA.