By Scott Kim|Friday, December 1, 2000

Clip Joints

Henry Petroski, professor of civil engineering at Duke University, writes about the fascinating histories behind everyday objects. He devoted a whole chapter of his book Invention by Design (Harvard University Press, 1996) to the paper clip. The invention of the classic Gem clip, in 1899, spawned numerous competitors. Above are drawings of just a few that have been patented over the years. Can you match each clip with the description of its advantages at right?

1.  The classic Gem paper clip
2.  Holds more, easier to apply
3.  Patented around the time of the Gem clip's invention
4.  A Gem clip competitor that uses less wire
5.  Librarians like it because the long legs reduce tearing
6.  Slides onto paper without the need to first spread the loops
7.  Slips on from either end; endless wire eliminates tearing
8.  Similar to the Gem clip, but lengthened legs eliminate tearing
9.  Slides on easily from either end; whichever way it is applied, the clip always protrudes beyond the edge of the paper

See My Point?
In Petroski's The Pencil (Knopf, 1990), he reports that in 1981 the Engineering News-Record printed a large, colorful drawing of a pencil on its cover. Unfortunately the drawing contained several errors, which the readers gleefully pointed out in a deluge of mail. Here is a modified version of that drawing. Can you spot four errors? Assume you are looking at a typical number 2 pencil directly from the side.

Accidental Inventions
Can you match the 10 famous inventions below with the surprising circumstances that led to their discovery? For the full stories, along with other serendipitous breakthroughs, see Accidents May Happen by Charlotte Foltz Jones (Delacorte Press, 1996) and They All Laughed by Ira Flatow (HarperCollins, 1992).

1. In 1825, Jean-Baptiste Jolly spilled an oil lamp containing distilled turpentine on his wife's tablecloth.

2. In the mid-1800s, Swedish chemist Alfred Nobel was transporting a sensitive material in glass flasks packed in soil when one of the flasks broke.

3. In 1859, Robert Chesebrough watched oil-field workers scrubbing a waxy substance off their machinery.

4. In the early 1900s, French scientist René -Antoine Ferchault de Réaumur paused to study a wasp's empty nest.

5. In the early 1920s, businessman Donald Duncan saw a weapon from the Philippines that could be quickly retrieved if the hunter missed the target.

6. In 1938, DuPont research chemist Roy J. Plunkett was surprised when an experimental refrigerant turned from a gas into an oily white powder.

7. In 1942, Percy Le Baron Spencer was working with radar equipment at Raytheon when he noticed that a candy bar had melted in his pocket.

8. In the 1950s, George de Mestral came home from a walk in the woods to find his jacket covered with cockleburs.

9. In 1965, Dr. James Schlatter was developing a new drug to treat ulcers when he spilled some on his fingers.

10. In 1982, researchers at a Japanese laboratory used superglue to fix a crack in a fish tank.
  a. Yo-yo

b. Velcro

c. Teflon

d. Vaseline

e. Dynamite

f. NutraSweet

g. Dry cleaning

h. Modern paper

i. Microwave oven

j. Modern fingerprinting


Want to see the solution to this puzzle?

Got new solutions for the puzzle? Want to see other people's solutions? Talk to the puzzle master in his discussion forum at

© Copyright 2000 The Walt Disney
Comment on this article