Nuts And Bolts On A Pedestal

Edward Tenner (“Pantheons of Nuts and Bolts,” Winter 1989) gleefully informs us that the great museums of technology all over the Free World have been conquered by his ilk, the social historians, who are busy throwing out the inventions to make room for exhibits of the pseudoissues they think the public should consider more important. Exhibits on social issues are far less interesting to the actual attendees of technology museums than the real machinery. The machinery made the world prosperous, while the social exhibits are just boring propaganda that won’t improve the world at all. There is probably no way to correct this situation. Getting institutional power is a profession, and professionals will beat amateurs every time.

Every so often an industrialist gets the good idea of commemorating the technology on which his success is based. Unless he is ashamed of his accomplishments, he needs to be careful to avoid his museum’s getting into the hands of the social historians, the public-policy community, the museum community, or the educationists.

Professor John McCarthy
Department of Computer Science
Stanford University
Stanford, Calif.

Nuts And Bolts On A Pedestal

I was particularly impressed by Edward Tenner’s article. I have visited all three of the museums he discussed many times. I find I feel most comfortable in the London Science Museum, as it breaks down each discipline and shows its development. The Munich museum becomes a little confusing by its voluminous treatment of alternative developments, and the Washington museum tries to be everything to everyone—but has been able to address the full range of associations of man and machine. I’d sum them up: Washington—man and his machine; Munich—man’s machines; London- the development of the machine.

Your publication captures the spirit of invention and discovery and stimulates a lot of thought and pleasure.

I. Martin Spier
New York, N.Y.

Quick Rising

Your article on the history of escalators (“Early Risers,” by William Worthington, Jr., Winter 1989) was fascinating. Mr. Worthington says very little about the speed of escalators though. The goal of greater speed motivated us at TRW in the late 1960s when we were studying ground-transportation systems. Moving sidewalks were among the concepts studied, and, recognizing the human limitation of stepping across a moving interface with more than a few-miles-per-hour speed difference, Dr. Andrew G. Hammitt invented a variable-speed conveyor that could transport people much faster.

He recognized that if one velocity component is kept small—the one parallel to a person’s walking direction upon embarking onto the sliding treads—a person could make this transition easily and then turn to face a new direction of faster motion. After a series of small transitions, while executing a gentle turn, the speed in the principal direction of motion could be quite large.

His concept can be demonstrated visually by using a paper model. Cut out from a sheet of paper a long Sshaped slot with initial and final ends parallel. Then overlay the sheet (minus that S-shaped panel) on a second sheet marked with evenly spaced parallel lines perpendicular to the ends of the “S.” Slide the sheets and watch the movement of the lines.

At the time, I was responsible for patent licensing at TRW. Imagine our surprise to discover that the English had beaten us to the idea and had even built and installed at least one demonstration unit. For reasons unknown to me, this concept has never caught on. I still believe it offers much potential.

C. Budd Cohen
Redondo Beach, Calif.

The Hawk’s Eye

What a great cover you picked for the Winter 1989 issue! And then you spoiled it by declaring the Hawk a “heat-seeking” missile (on your contents-page caption).

H. Joachim Maitre
Director, Center for Defense Journalism
Boston University
Boston, Mass.

Editor’s note: The Hawk system uses pulse and continuous-wave radars and proportional guidance combined with semi-active terminal homing.

Inside The Blue Box

The article on Mr. Link’s magic blue box (“The Planes That Never Leave the Ground,” by James I. Killgore, Winter 1989) brought back many memories to this cadet pilot trainee of 1942 and 1943. None of us knew what went on in the pedestal, how it worked, or even who Mr. Link was, but the little blue box with the yellow wings humbled many of us on our first “flights.”

A few spins and stalls in something that seemed uncontrollable gave us a real appreciation of simulator work once we got it mastered. One unforgettable thing was the ability of the instructor at his desk to turn on wind or rough air—if the cadet inside thought things were too easy.

Paul C. Hassler, Professor Emeritus
Department of Civil Engineering
University of Texas
El Paso, Tex.