ENCYCLOPEDIA OF AVIATION, (Scribner's, $14.95) is an alphabetical source-book of words and picture for students of flight. Brief text-blocks are combined with more than 250 black-and-white photographs and drawings to illustrate most of the wings of man, from the early turn-of-the century contraptions to the latest NASA projectiles. Prinicipally useful as an identification and histrical reference book for various kinds of aircraft, there are also short sections of the mechanics and production aspects of aircraft. It sometimes takes more diligence than you may have bargained on the find a desired entry (the justly esteemed Aero Spacelines Pregnant Guppy cargo plan, for example, is listed under G for "guppy"; and the Consolidated B-24 bomber of World War II fame is under L for "Liberator"), but in general this compact and efficient volume shouls satisfy both the casual browser and the enthusiastic wing-watcher.

THE INTERNATIONAL ENCYLCLOPEDIA OF AVIATION, edited by David Mondey et al . (Crown, $250 is scarcely similar to the Scribner's book. With almost 500 pages and more than 1200 illustrations (about half in color), the International Encyclopedia glides at a more leisurely pace, but to greater heights. It traces the history of flight from its earliest origins, including experiments with related adventures such as kites and gliders, through the evolution of various propulsion devices, and the rise of rocketry and space travel. Attempts are made to show how an airplane is flown, to explain the rudiments of wing and fuselage design and to illustrate the basic physics of flight; but most of the space is taken up with pictures and descriptions of the vehicles man has flown, and with the variety of forms (balloons, helicopters and airships, among others) and spin-off disciplines like aerospace medicine and military hardware. A compendium of flying facts, feats and records concludes this handsome and worthwhie collection.

DECADE OF THE TRAINS: The 1940s, by Don Ball, Jr. and Rogers E. M. Whitaker (New York Graphic Society, $24.95) is concerned with more down-to-earth transportation. Perhaps only a true railroad buff can fully appreciate this collection of photos and lively accompanying prose from the last great period of railroad expansion and grandeur, but anyone can find in it a lost part of American life: the smoking, rushing, near-deafening excitement of huge locomotives with hundreds of tons of war materials in tow, roaring across the wide landscape of nation at arms. The many photographs (all in black-and-white) capture vividly the power and mood of the final years of the rail age. For those who remember the period, this book should provoke powerful nostalgia; for those too young to have known it, it is a vicarious thrill.

SHIPS, by Enzo Angelucci and Attilio Cucari (McGraw-Hill, $19.95), despite its austere title, is an opulently illustrated account of mankind's 10,000 years at sea. Form the humblest hollowed-out tree trunk to awesome warships and super tankers, to specialized bathyscapes and hydrofoils, Ships is a history of the variously ludicrous, beautiful, courageous or ghastly ways in which human beings have tried to keep their heads above water.About half of the book is devoted to fluid transport before the 20th century, and the numerous drawings illustrate its evolution from ungainly constructions of bound reeds or inflated sea-lion skins to Greek and Roman biremes to the Viking explorations to the great era of clippers ships. The second half deals with the more recent advent of the merchant marine, the warships of various nations, nuclear submarines and the like. Finally, nearly 100 pages of appendix material provide an extremely useful glossary of marine terms, an illustrated guide to the types and classes of boats and ships, and a roster of technical data on the ships used in World War II.

SAIL, STEAM AND SPLENDOUR: A Picture History of Life Aboard the Transatlantic Liners, by Byron S. Miller (Times Books, $35). Anyone who has traveled by air to Europe, cramped for six or seven hours into a space half the size of a phone booth, cannot help but be astonished at the unspeakable luxury in which the gentry once sailed there. After a substantial demand for passage developed in the early 19th century, and particularly after the advent of steam power, the great lines began of compete vigorously for the tourist dollar with accomodations and amenities that could make Versailles look like a bus station. Although Miller's book spans the entire history of the crossing trade, its wealth of drawings and photographs rightly concentrate on the high season from the turn of the century to the 1940s, when the patrons of such leviathans as the Mauretania, Lusitania, the stupefying Ile de France or the record-setting United States were regaled with an ocean-going grandeur unimaginable in this time. Readers curious to know how travelers played golf on deck, dined under 20-foot palm trees in rooms two stories high, shot skeet off the side or went wety idle in the Roman baths will find it all here, along with the roles of the great ships during wartime - and the peacetime wars between the steamship lines themselves.