THE U.S. TREASURY DEPARTMENT, WHICH HAD NOT RE designed our paper money since 1929, has done so twice in the past decade. The reason: worries that counterfeiters were about to get the upper hand in the neverending technological duel between currency makers and currency fakers. Ever since money was invented, people have been trying to pass off imitations as the real thing, and America’s rich history of counterfeiting goes back as far as the first European settlers.

WHAT’S THE BEST WAY TO CONVERT ONE’S THOUGHTS INTO data? For millennia, the answer was writing and drawing by hand. But when computers came along, this time-honored method was supplanted by keyboards, punch cards, and other intermediaries. Today handwritten input to computers, while still far from perfect, is becoming increasingly common—for handheld devices, Asian languages with thousands of characters, design software that combines words and images, and signature verification, among other uses.

THE GRASSY EXPANSE WHERE THE WRIGHTS did their 1904 and 1905 experiments survives today as a historic enclave on the property of Wright-Patterson Air Force Base in Dayton. The only structures are replicas of the 1905 hangar and launching catapult. The site also includes Ohio’s largest remaining tallgrass prairie, so it’s a nature as well as a history preserve. It is overlooked by a 17-foot obelisk that was dedicated on Orville Wright’s birthday in 1940 (he was present).

ON OCTOBER 31, 1952, HALLOWEEN WAS JUST GETTING ROLL ing in California when, half a world away on the South Pacific island of Elugelab, the firing circuits closed on Ivy-Mike, the first practical test of the prototype hydrogen bomb. Ghosts and goblins roamed the Berkeley streets as Dr. Edward Teller, the driving force behind the new weapon, sat quietly in a darkened basement, patiently scanning for subtle, indirect evidence that he had irrevocably altered the world yet again.

John Hall, a mechanic working with Thomas Paine, wrote after the Revolution of the “saints”— inventors, innovators, and artisans—who were doing their best to make the new nation endure. Some of their best work involved building bridges across the land’s rivers and streams and valleys, a key to opening wilderness and connecting farflung communities. In fact, Paine, with Hall’s help, devoted much of his later career to designing and trying to sell an iron bridge.

WE FIRST PUBLISHED INVENTION & TECHNOLOGY 20 years ago this issue, and we announced that we were doing so because “for both good and bad, the modern is the technological in almost every arena of life.” We also observed that “although interest in the history of technology has grown in the last few decades, the field itself is relatively new…. A gap exists between the findings of the scholars and the educated public.”

KITTY HAWK, NORTH CAROLINA, IS A place justly famed, for there on December 17,1903, Wilbur and Orville Wright demonstrated that heavier-than-air flight was possible. Huffman Prairie, Ohio, is a place unjustly ignored, for in that 85-acre pasture in 1904 and 1905 the Wrights converted flight from the barely possible to the truly practical. At Kitty Hawk the Wrights made four flights, their best being WiIbur’s wavering voyage of 852 feet in a machine he struggled to keep airborne.

AN UNFRAMED PHOTOCOPY OF THE FIRST ATOMIC BOMB EVER built has been pinned to my workshop wall for at least five years now. It’s from a modern edition of The Los Alamos Primer , a book of the lectures given in 1943 by a physicist named Robert Serber to introduce new Los Alamos laboratory personnel to the task at hand. That first bomb was set off in the American desert in the summer of 1945, after two years of intense work by thousands of people.

ALONE IN HIS ONE-HORSE BUGGY, SLOGGING DOWN A RUTTED road in 1803 to yet another courthouse in the heat of a Georgia summer, Eli Whitney must have felt like a man taunted by the allure of a beautiful woman who was everyone’s lover but his. Wherever he looked oceans of upland cotton undulated in all directions, just out of reach. The crop offered unparalleled wealth to thousands of Southern plantation owners and their families but not to Whitney, a cruel taunt indeed, since his mechanical genius was solely responsible for that wealth.

MORE THAN TWO DECADES AGO AN UNPRECEDENTED GLOBAL medical crisis began. Mysterious, deadly, and unexpected, an epidemic with an unknown cause started to claim victims in odd, seemingly unrelated groups. Gay men. Intravenous drug abusers. Africans. Haitians. Hemophiliacs. As the list grew, physicians worldwide slowly realized they were facing a truly new and powerful enemy.

AS THIS ISSUE’S STORY on catalytic cracking shows, the triumph of America’s oilrefining industry in the twentieth century was based on two things: discovering clever new processes and then scaling them up to produce Yuige quantities. Yet alongside the mammoth refineries that pumped out high-octane gasoline to defeat the Axis, there were hundreds of small units distilling kerosene and heating oil for local communities, just as in the industry’s pioneer days.

FOR YEARS, MOST PEO ple have regarded “pizza” and “frozen pizza” as two distinct species of food. Americans love pizza, especially when you can make a phone call and have it delivered to your door still hot from the oven. Frozen pizza, by contrast, was long considered the dinner of last resort. Frozen pizza has been around for at least 50 years, but only in the last decade have manufacturers been able to make one that rivals the quality of fresh-baked.

INVENTION & TECH nology used to have a column called “They’re Still There,” about antiquated industrial equipment that was still in use. Its author came to be known as the Grim Reaper because all too often, the subject of a column was shut down soon after publication. Sometimes, however, technology has the last laugh. “They’re Still There” is long gone, but two of its subjects that expired shortly after their write-ups have turned out to be surprisingly lively after all.

WITH MOST TECHNOLOGIES, ONE CAN look back and point to a certain period when development was at its most feverish. Who wouldn’t want to have lived in Detroit in the 1910s or Silicon Valley in the 1970s? Today’s cars and computers may run much more smoothly, but the thrill of seeing them take shape is long gone.

THE SPRING 2005 ARTI cle on the history of the microwave oven (“‘The Greatest Discovery Since Fire,’” by William Hammack) reminds me of how my father saved the day for Raytheon. In 1958 a newfangled gadget called a Radarange was brought to Minnesota Power and Light in Duluth for a demonstration. Appliances were a big thing for power companies in those days, and this was one big appliance. The day before the demonstration, the unit was set up and tested, and it failed to operate. Nobody knew how to fix it.

POLITICIANS LIKE TO call a feeble, shortterm patch-up of a major, long-term problem a “Band-Aid solution.” Some delegates at the 2004 Republican National Convention wore adhesive bandages with purple hearts to belittle an injury for which John Kerry had received a Purple Heart. But when Earle Dickson invented the adhesive bandage in 1920, he saw it as an ingenious and effective solution to a serious problem. In doing so, he created an immensely useful product as well as a universally recognized brand.

The Electric Guitar And Me

THE LINE ON YOUR SUM mer 2004 cover featuring the electric guitar—“An invention that changed the whole world of music”—reminded me of the line that Life magazine used on its June 28, 1968, cover featuring me and my Jefferson Airplane band mates: “Music that’s hooked the whole vibrating world.” Just a few years earlier I had been immersed in traditional music on the acoustic guitar (as I am now again). I had eschewed all things electric.

HISTORIANS LIKE TO ORGANIZE THEIR SUBJECT AROUND A single overarching theme. All of American history, for example, can be understood in terms of slavery and its aftermath, or the changing roles of women, or the development of technology. In the movie Zoolander (2001), American history is presented as a series of conspiracies by the fashion industry.

BEFORE DEPARTING ON HIS DOOMED MISSION ON FEB ruary 17, 1864, Lt. George Dixon slipped a $20 gold piece into his pocket. The young Confederate’s sweetheart had given him the coin for good luck, and so far it had worked better than she could have dreamed. At the Battle of Shiloh the coin had deflected a Union bullet and saved Dixon’s life. The lieutenant called the dented disk his “life preserver.”