by Henry Petroski, 1996, 242 pages, $24.95, ISBN-0-674-46367-6.
The author of this book starts out by saying, "As simple as familiar objects may seem at first glance, their conception, development, manufacturing and marketing may pose great difficulties". He goes on to prove that this is true by citing the histories of some very familiar items.
His first example is the ordinary paper clip. Literally hundreds of improvement patents have been issued, yet it is still not "perfected". The most common clip was given its present form by a company called Gem Ltd. in the last century and is still referred to in the industry as the "Gem" clip. Inventors are still trying to overcome its negative features. The author lists several shortcomings such as its tendency to tear paper, requiring its loops to be spread when clipping on, and its habit of slipping off thick stacks of paper.
Next he considers the common wood-cased pencil. When wax was added to the lead for smoother writing and added to the wood for easier sharpening, the lead often separated from the wood and would break when the pencil was used or even when dropped. Etching the lead surface and coating it with a suitable chemical solved this problem. However, overcoming the BOPP (Broken-Off Pencil Point) problem has not been as easy. Understanding why points fracture as they do is far from as simple as you might think.
His next case history is that of the zipper. In patent literature, they go back to 1851! The description of its evolution is fascinating. There is a great sketch of the tooling that applies the zipper teeth to the fabric.
The author notes how ideas often come unexpectedly -- but usually to individuals who can see the idea's potential. He relates how de Mestral, after walking his dog in the Alpine woodlands, saw cockleburs on his trousers and on his dog's fur -- and saw the potential for what became Velcro.
Yet another captivating case history is the section on plastic zippers. He details the story from an inventor in Denmark, to British investors, to refugees from Romania, to a Japanese inventor who extruded tubular film with grips -- which became the familiar Ziplock.
The author notes how the acronym, MAYA, has become the buzz term for designers. It stands for Most Advanced Yet Acceptable. In other words, if your invention is too different from present designs, it may not find acceptance.
The history of aluminum cans provides fodder for another exciting chapter. Here is a product that must use a very minimum of material and still safely resist 100 pounds per square inch of pressure. However, it must readily "fail" when the pop-top is actuated. Some 100 billion(!) beverage cans are made each year. Think what a design savings of a few percent of aluminum would be worth to the industry.
The sketch of Alexander Bain's facsimile machine of 1843 will shake up those who think the fax machine is the latest thing in technology. In this rundown on the evolution of the fax, the author notes how consumers often decide the winning technology. He cites the victory of the VHS video cassette over the technically better (picture quality) of the Beta cassette.
When inventing and engineering, the human factor must never be forgotten. A computer-controlled airplane crashed because a pilot mistook a rate-of-descent display reading of 33 for 3.3!
That an art is old and simple does not mean design caution is not required. A Roman aquaduct in 97 AD delivered 40 million gallons of water daily to Rome. Yet when New York's World Trade Center, 110 stories high, was completed in 1973, it was found that the water pressure was not high enough to properly flush toilets on the observation deck!
There are no equations or computations in this book -- it is an easy read. It beautifully conveys the lesson that there are no "simple" inventions -- and no such thing as "routine" designing.