Ericsson’s caloric engine had four 2-part cylinders. The upper, or supply, cylinder drew in air from the outside and compressed it; in the lower, or working, cylinder the air was heated to provide power. The pistons in these two cylinders were connected with rigid rods; they moved in tandem. During a downstroke ambient air entered the supply cylinder while “used” air was exhausted from the working cylinder.

the year was 1893, and the Midwest was experiencing World’s Fair fever. Chicago’s town fathers, eager to show that their prairie city was more than just a cow town, had created a grand spectacle to celebrate (a year late) the four-hundredth anniversary of the discovery of America. Columbus may have been the excuse, but from the day of its opening the theme of the Columbian Exposition, like that of most world’s fairs, was Progress.

As early as 1847 Daniel Webster could say without sounding ludicrous that the railroad “towers above all other inventions of this or the preceding age.” Indeed, by the 1860s American railroads had triumphed over competing forms of transport for most long-distance travel. Shippers welcomed the dependability of year-round rail service. It was cheaper than the turnpike, more flexible and direct than the canal packet or the steamboat, and much faster than any of these.

After reading the article “A Few Words About This Picture” (by Bobby Lowich, Fall 1992), I am left to wonder if old photographs can be trusted. Experience, however, has taught me that they do tell the truth, and that problems arise from interpretation. This is an interesting article, but I think the photo needs further study.

The year was 1893, and the Midwest was experiencing World’s Fair fever. Chicago’s town fathers, eager to show that their prairie city was more than just a cow town, had created a grand spectacle to celebrate (a year late) the four-hundredth anniversary of the discovery of America. Columbus may have been the excuse, but from the day of its opening the theme of the Columbian Exposition, like that of most world’s fairs, was Progress.

The humble, everyday coat hanger would seem to have existed unchanged forever. But in fact, its current pure form is the result of vigorous experimentation. As recently as 1897 Sears, Roebuck copywriters had to tell customers why they needed one in the first place (“Garments when hung on this device do not lose their shape as when hung on hook or nail”). Nevertheless, by then hangers existed in as many different forms as that more famous example of nineteenth-century inventive fecundity, the apple parer.

Early one October morning in 1939, an improbable vehicle lumbered out of Chicago on the first leg of a long and eventful trip to Boston. It looked like something from the mind of H. G. Wells, with its high, slanted turret and red and silver paint. It was so huge that the roads it traveled had to be closed to other traffic.

CHARLOTTESVILLE, VA. : On a February weekend when the NBA’s All-Stars were in Utah for their annual contest, an equally stellar (though somewhat less wealthy) group assembled at the University of Virginia for a symposium on trends in technology. There were no acrobatic jams, but the scholars did occasionally slamdunk one another’s theories; and while they may not exactly have lit up any scoreboards, many impressive points were tallied.

In 1915 San Francisco threw a tremendous party—the Panama-Pacific International Exposition—to ratify the city’s recovery from the 1906 earthquake. Among the guests were several machines sent by the Lanston Monotype Company of Philadelphia to demonstrate the speed, fluency, and accuracy with which they cast type. These were in the care of a Massachusetts printer named George W. Mackenzie, and when the fair was over, he bought them and set up the first Monotype composition plant in San Francisco.

The men are gathered at eight o’clock in the cold, clear air of a late-April morning. Most have walked to the meeting, carrying long-handled shovels and bramble cutters on their shoulders. In groups of two or three they have ambled along the dusty gravel road overlooking New Mexico’s Valdez Valley until they reached the unmarked bend that serves as the meeting place. Others came crowded six to a pickup cab, then spilled out and grabbed shovels and hats from the back of the truck.

Benjamin Franklin, in charge of all things wise, was the American ambassador to France when he witnessed the successful ascent of an unmanned hydrogen-filled balloon on August 27, 1783. As the twelve-foot globe shot up in the sky until it seemed no bigger than an orange, a skeptic said the flight was interesting but wondered what use it could have. Franklin, our history primers tell us, growled, “What use is a new born babe?”

Historians of technology have come to their calling by diverse paths, many from general history, some from journalism, some from engineering, and more and more from academic programs focused on technology and society. Few have had as unusual a pilgrimage as John Michael Staudenmaier, the author of Technology’s Storytellers , a prizewinning analysis of the emergence of the history of technology as a coherent intellectual discipline.

NEW YORK, N.Y. : Why did the Tacoma Narrows Bridge collapse? The famous fiasco is a staple of introductory physics classes. Few students can forget seeing the grainy black-and-white film of the 1940 incident: the bridge ripples gently at first, then starts heaving and twisting with fearsome amplitude until finally, shockingly, it breaks apart.

Until the 1960s a student in an American engineering school was expected by his teachers to use his mind’s eye to examine things that engineers had designed—to look at them, listen to them, walk around them, and thus develop an intuitive “feel” for the way the material world works and sometimes doesn’t work. Students developed a sense of form and proportion by drawing and redrawing. They acquired a knowledge of materials in testing laboratories, foundries, and metalworking shops.

Half the world has seen the Newtown Holder Station, but you’ll never hear anyone call it that. The two huge canisters that rise above the flat landscape of Queens, maddeningly familiar monuments to the tens of thousands of motorists jammed in the traffic that strains from Manhattan toward the beaches and communities of Long Island, are “the Elmhurst gas tanks.”

Early on the morning of January 3,1944, a series of explosions ripped through the hull of a U.S. Navy destroyer that lay at anchor two miles south of New York City. The blast shook the entire metropolitan area, rattling plates and awakening people as far away as Westchester County, twenty-five miles to the north. As the flaming vessel sank, a swarm of boats from the Coast Guard Station at Sandy Hook, New Jersey, converged on it and began evacuating the 163 survivors. Fifty or more sailors had suffered burns and other injuries, many of them critical.

Tuesday, January 11, 1853, dawned clear and chilly, but despite the cold, Battery Park in lower Manhattan was thronged with curious spectators waiting to see the trial run of the Ericsson , a great ship powered not by wind or steam but by “caloric”—hot air. History was in the making; the Age of Caloric lay just ahead.

A Few Words About That Taxi

After reading the article “A Few Words About This Picture” (by Bobby Lowich, Fall 1992), I am left to wonder if old photographs can be trusted. Experience, however, has taught me that they do tell the truth, and that problems arise from interpretation. This is an interesting article, but I think the photo needs further study.

Half the world has seen the Newtown Holder Station, but you’ll never hear anyone call it that. The two huge canisters that rise above the flat landscape of Queens, maddeningly familiar monuments to the tens of thousands of motorists jammed in the traffic that strains from Manhattan toward the beaches and communities of Long Island, are “the Elmhurst gas tanks.”

Perhaps the most complicated piece of machinery built by hand in the world today is a Steinway Model D grand piano. The eight-foot-eleven-and-three-quarter-inch grand that is the favorite of concert pianists the world over has twelve thousand parts; it takes a year to make and roughly $60,000 to buy. It is built in a factory in Queens, New York, by a process that has hardly changed in a hundred years.