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LETTERS
The First Issue
We received more than two hundred letters commenting on our first issue, which appeared last summer. Here are a few:
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The First Issue
What a superb first issue! The articles about Salk and Edison are gems. The interview with Elting E. Morison (I have had those two books of his on technology for some years) is most welcome. And the writing is remarkably lucid.
Burnett Cross
Hartsdale, N.Y
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The First Issue
Your magazine takes aim at technology at just about the right level and hits the bull’s-eye. The selected references to books that previously escaped my attention are especially intriguing. Maybe I’ll catch up with them, per your articles’ enthusiastic recommendations.
Henry S. Thomassen
Peoria, Ill.
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The First Issue
As manager of engineering for Lockheed’s Advanced Marine Systems, I can guarantee your magazine will be seen by my engineering staff—after I’ve read it, of course.
H. G. Schreiber
Santa Clara, Calif.
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The First Issue
You have identified a real educational need, and I expect that you will more than meet it. Your format, illustrations, and presentation are all first class.
John G. Nee, Professor of Industrial and Engineering Technology
Central Michigan University
Mount Pleasant, Mich.
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The First Issue
Your magazine fills a vital niche in the modern world of technology—a niche that has been vacant too long. I was particularly intrigued by Thomas Hughes’s “The Graphic Truth,” because I find that a great many of my colleagues are totally unable to comprehend or properly utilize quantitative data presented pictorially.
Robert S. Duschatko
Kingwood, Tex. |
Before the Europeans
I think Invention & Technology serves an important need, but I must register my objection to your definition of what technology is American enough for inclusion. You propose to examine inventions and technologies “from the first European settlers who brought with them the advanced technologies of their day.” But when Europeans arrived in the New World they also found advanced technologies, some of which were incorporated into their technology. A few examples: 250 miles of prehistoric irrigation canals in the Phoenix area, some of which formed the nucleus of the canal systems built in the late nineteenth century; energy-efficient housing designs, including pit houses (earth-loaded for insulation) and pueblos; domestication of plants, including corn, potatoes, and beans, that are staples in many parts of the world. If you are celebrating all American technology except for that invented by the first Americans, you are committing an oversight that is an anachronism in today’s society.
Michael B. Schiffer, Director,
Laboratory of Traditional Technology
University of Arizona
Tucson, Ariz.
We fully agree that the technology originated by American Indians is part of the nation’s technological heritage, and we plan to explore aspects of it in future issues.
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Coating the Big Mirror
The article on the Hale Telescope at Palomar indicates that the reflective aluminum surface of the mirror was applied after the mirror was delivered to the observatory, but there is no discussion of the aluminizing process. It must have been quite an accomplishment and would, I am sure, be of interest to the students in my vacuum-technology course. Can you provide any insight into the procedure?
Wayne E. Phillips
Associate Professor of Mechanical Engineering Technology
Oregon Institute of Technology
Klamath Falls, Ore.
According to Dr. Robert Brucato, assistant director of the observatory, the mirror’s aluminum reflective surface needs to be replaced about every three years due to deterioration. First the fourteenton mirror is taken off the telescope; then the aluminum is removed from the mirror with a dilute acid solution. Next, the underlying glass is cleaned, first with soap and water, later with solvents. After this, the mirror is placed in a vacuum chamber—every major observatory has one for this purpose—for a final cleaning by ion bombardment to remove any remaining contaminants and then for the application of a new surface. The chamber is lined with tungsten filaments wound into loose coils. To each of these is attached a precise amount of aluminum. When an electric current is passed through the coils, they heat up, and the aluminum melts and vaporizes. Aluminum atoms, streaming across the chamber, coat the mirror in an even layer several atoms thick. After the 180 pairs of filaments have been shot off, two at a time, the job is complete, and the mirror is removed from the chamber. |
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