PITTSBURGH, PA.: America’s rivers used to come in two varieties: pretty and working. The pretty ones attracted lovers, poets, and artists; the working ones stank, turned orange, caught on fire, and blighted the landscape. At first the two could be combined, as with a little old stone mill and its handsome, inefficient water wheel. But once manufacturers started learning about hydraulics and discovered economies of scale, beauty and industry went separate ways.

Today many rivers are seeing the opposite end of the process: factories closing up, leaving the shoreline littered with derelict works. In Pittsburgh, which knows more than most places about rivers and deindustrialization, civic leaders have decided to turn the largely abandoned riverfront, bleak as only an industrial archeologist could love, into an inspiring vista with a distinct Pittsburgh flavor.

The result is Riverwalk, a collection of imposing artifacts from the region’s industrial past that have been rescued from the salvage market. Thirteen pieces of obsolete equipment have already been strung out over a few hundred yards of the Monongahela’s south shore by Riverwalk’s managing body, the Pittsburgh History and Landmarks Foundation. When completed, the outdoor park and museum will be a mile long, with equipment and machines from the many industries that built Pittsburgh: oil, coal, coke, iron, steel, aluminum, electrical goods, and transportation.

To describe the artifacts on display requires tossing around enormous figures as casually as a congressman discussing the budget. A 600-ton Mesta blowing engine has two 24-foot flywheels with a piston arrangement of similar size above them. A petroleum vacuum-distillation tower, when installed, will stretch 45 feet into the sky, dwarfing a 30-foot Bessemer converter. Touring the site is enough to make anyone feel like a toddler crawling under the kitchen table.

Riverwalk winds through an urban-renewal project called Station Square, where restaurants and boutiques have sprung up alongside the weeds growing through abandoned railroad tracks. The effect is disconcerting; one wonders what the old trainmen would think of brightly painted cabooses selling flowers and cookie cutters on a site where coal and iron were once unloaded. Yet the industrial artifacts would certainly make them, or any old-time resident of Pittsburgh, feel right at home. And when finished, Riverwalk promises to do what once seemed impossible: turn the workaday Monongahela, as it flows through the middle of a large city, into a scenic river.

NEW YORK, N.Y.: Scholars who take an excessively abstract approach to the past are sometimes accused of writing history with the people left out. In similar fashion, many engineering historians write history with the equations left out. The reason is simple: At the first appearance of an exponent or square-root symbol, 95 percent of typical readers feel an immediate urge to find out what’s on television. Boldly ignoring this obstacle, David P. Billington has written The Innovators: The Engineering Pioneers Who Made America Modern (John Wiley & Sons) in an attempt to show how calculations of bending moment and flux density have influenced history just as much as wars and elections.

Billington’s algebraic bias is understandable, because he has been a structural engineer since the early 1950s. Besides writing a widely used textbook on thin-shell concrete structures, Billington has delved deeply into the artistic side of his discipline with such books as The Tower and the Bridge (1983). His work shows how the world’s classic designs have resulted from a seamless blending of engineering and aesthetic concerns, while excessive attention to one or the other generally leads to failure.

In The Innovators Billington explains how mechanics and aesthetics alike are governed by fundamental physical constraints—elastic limits, Ohm’s law, the unyielding principles of thermodynamics. For example, the development of different types of steam engines for power plants, locomotives, and boats can be traced to formulas for power production and longitudinal stresses in boilers and how they interact with the varying importance of size and weight. Billington also shows quantitatively how James Eads could be sure that his radical arch design for the St. Louis Bridge would hold up, thanks to the much greater tensile strength of steel as opposed to iron.

Some of Billington’s innovators are familiar: Fulton, Morse, Edison. Others are less so, such as James B. Francis and Uriah Boyden, who developed the basic theory of hydraulics while designing a waterpower system for Lowell, Massachusetts. And however daunting the formulas may appear at first glance, they turn out to contain nothing that would stump a high school math student. The few cases where calculus is brought in are confined to the footnotes.

The Innovators concisely summarizes how America changed between the 1780s, when John Fitch and James Rumsey were struggling to make their rudimentary steamboats run, and the 1880s, when the mighty Brooklyn Bridge spanned New York’s East River. By giving a working engineer’s perspective on how these transformations took place, Billington adds another dimension to our understanding of how we got where we are.

NEW HAVEN, CONN.: When Charles Sheeler and Margaret Bourke-White photographed factories and machines in the 1920s, their work was the epitome of machine-age modernism . By the time David Plowden graduated from Yale in 1955, the atomic and space ages were under way and the term modernism was as quaint as the worn-out industrial equipment that had been so new in Calvin Coolidge’s day. In his four decades as a professional photographer, Plowden has seen steam disappear from the nation’s railroads and waterways, steel towns turn into the Rust Belt, and farming become agribusiness. His pictures of disappearing ways of life form a wistful counterpoint to the technophilic optimism of an earlier era. After a lifetime spent documenting these transformations with words and images, Plowden has given his voluminous archives to his alma mater’s Beinecke Rare Book and Manuscript Library.

The collection will eventually contain more than eight thousand negatives and prints as well as notes, correspondence, drafts, and journals. Starting this summer, they will be available to scholars from Yale and elsewhere, who can see how Plowden’s work took shape and how his photography evolved through the years. A major exhibition is planned for the fall of 1997. The papers will be housed in the Yale Collection of Western Americana—geographically imprecise but appropriate nonetheless. Invention & Technology readers will remember Plowden’s Spring 1995 article “The Glory That Was Buffalo.” Like the animal for which it is named, millions of which once roamed the Great Plains, industrial Buffalo is part of a vanishing breed that once symbolized America. Plowden and Yale hope to keep the breed alive even when its heyday is long past.

ANNAPOLIS, MD.: The designers of America’s space program knew that they would be sending two very different types of things into the sky: machines and men. Development of the machinery that would take us to the moon was lavishly funded from the start of the Cold War, and even more so after the Soviet Union’s Sputnik launch in 1957. Training men to make the trip, by contrast, was largely catch-as-catch-can. The reason was simple: You can’t know how astronauts will react in space without actually putting them there. Yet much valuable information about the behavior of their bodies and minds was obtained with 150-year-old technology: balloons.

In The Pre-Astronauts (Naval Institute Press), Craig Ryan details the history of such upper-atmosphere balloon research projects as Strato-Lab, Manhigh, High Dive, and Excelsior. During the 1950s and early 1960s, a handful of scientists with much more vision than funding sent fearless pilots deep into the stratosphere, where they tested pressure suits and breathing equipment, explored and overcame the mental and physical dislocations of being miles above the clouds, and sometimes even jumped more than a hundred thousand feet back to earth. The research yielded knowledge that was applied to high-altitude flight and space travel, as well as some ideas that could have prevented tragedy, the researchers say, if NASA had only paid attention.

Low budgets led to some creative engineering. Air inside a pressurized chamber was cooled by simply blowing it over a can of water vented to the atmosphere. One open gondola was made of Venetian blinds attached to an aluminum framework. Neither of these ideas made it into Gemini or the X-15, but the balloonists did make important advances in parachute design, and physiological data from their flights formed the basis of the emerging discipline of space medicine. A decade before the disastrous launch-pad fire of Apollo I , whose capsule was filled with pure oxygen, Manhigh designers had anticipated the danger and avoided it with an oxygen-nitrogen-helium atmosphere. Veterans of that program also insist that the Challenger space-shuttle crew could have survived if NASA had adopted the high-altitude escape system they pioneered two decades earlier.

Ryan, an experienced technical writer, shows a deep understanding of the subject and explains it expertly to his readers. His prose can get overheated at times: One researcher is a “hell-bent genius ghost,” while another “continues to hurl his scientific arsenal against the realities of ignorance and suffering, fired by his own personal spark of missionary hatred.”The book is at its best when the author describes what it was like to ride a gasbag twenty miles into the air with only a few pressure hoses keeping you from the instant death of atmospheric exposure. Ryan vividly conveys the mixture of terror, exhilaration, and calm resolve that pilots felt while plunging near the speed of sound through temperatures of one hundred degrees below zero, and he makes a convincing case for the importance of balloon research, however unappreciated, underfunded, and unfashionable it may have been, in laying the groundwork for America’s space program.

NORTHRIDGE, CALIF.: “But when I became a man, I put away childish things.” So St. Paul told the Corinthians. In real life, of course, we never put away childish things; we just spend more money on them, which makes them adult. The urge to collect is irresistible, whether it’s baseball cards, Barbie dolls, Jackie Onassis’s fake pearls, or—of perhaps greater interest to Invention & Technology readers—toy construction sets.

The Southern California Meccano Club began in 1975, when six collectors of the European version of Erector met in Garden Grove, California, to show off their models and swap parts and advice. Since then it has grown to more than 250 members nationwide. It has also expanded its scope, as reflected in the 1986 addition of “and Erector” to the group’s name. The merits of Erector versus Meccano can be debated as fiercely as Macintosh versus Windows, though without the fundamentalist fervor that characterizes that dispute. While each side has its partisans (along with Märklin, Bilt-E-Z, Buildo, Mysto, and many other toy construction systems, past and present), they all get along well enough, especially since Meccano bought its competitor’s trademark and started marketing its own Erector sets in the early 1990s. Nowadays the main schism is Meccano versus Märklin. In keeping with this multiplicity of makers, there are a number of societies besides the Southern California Meccano and Erector Club (SCM&EC), including Canadian and international clubs and the A. C. Gilbert Heritage Society, named after the original maker of Erector.

Erector-type sets have been losing favor with American youth, probably because there’s nothing you can click on. And unlike, say, model trains, which are so cute that no one can resist picking them up (much to the dismay of their owners), some Erector models look no more like what they are meant to portray than Madonna looks like Marilyn Monroe. Yet a miniature version of a bridge or Ferris wheel—things that are actually made of girders—can be strikingly realistic, and the process of putting them together gives an excellent tactile education in structural mechanics. Construction sets allow the enthusiast to blend art and engineering in a way that makes every hobbyist a potential Roebling.

Besides the traditional cars, trucks, locomotives, and windmills, SCM&EC members have replicated the enormous “Herman the German” crane mentioned in this issue’s piece on the Panama Canal and even built a sixfoot model of HMS Victory , Admiral Nelson’s flagship at the Battle of Trafalgar. Recent newsletter articles have reviewed the sets marketed by Sears through the decades, discussed the safety-dictated switch from slot-head to Allen-head bolts, and assessed the relative merits of plastic and metal gears. The group also holds regional meetings at which enough information is exchanged to make each one a virtual Erectoral College. To find out more, write the SCM&EC at P.O. Box 7653, Porter Ranch Station, Northridge, CA 91327-7653.