June 29, 2005

Instruments for the Ink Pot

The problem solved by a pen is the delivery of a colored liquid to a surface in the form of a line that curves and twists. There are any number of devices that can put ink on paper as wavy lines, but they all have their limitations. Do an experiment to see for yourself.

Materials and Equipment

• ink (or food coloring)
• paper
• scissors
• ruler
• toothpick
• nail
• drinking straw (plastic or paper)
• pen nib in pen holder

Procedure

Dip the toothpick in the ink and draw a straight line from right to left on the piece of paper. When your hand reaches near the edge of the paper, lift it up and start another line at the left-hand side of the paper. Repeat until you run out of ink. Follow the same procedure using the nail. Cut the straw at an angle and use it as if it were a pen to repeat the procedure. Then use the pen nib in the pen holder.

Now, holding each item as if it were a pen, make continuous curling loops. Try to make the loops as uniform as possible. Use a freshly cut straw, not the straw you used to make the straight line.

Measure the length of the lines you drew. Count the number of loops you made before you ran out of ink.

Observations and Suggestions

Which writing instrument drew the longest line? Which was least effective? What were some of the problems of trying to draw loops with each instrument? What advantage did the straw have over the toothpick and nail? What was its biggest disadvantage?

Reprinted with permission from The Secret Life of School Supplies by Vicki Cobb. Published by J.B. Lippincott, New York. Text copyright © 1981 by Vicki Cobb ( www.vickicobb.com ).

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