Holmes and the e
In the story called Adventure of the Dancing Men, Sherlock Holmes, the
famous detective, solves a mystery by figuring out a message that is in
code. Holmes is aware that in English the letter e is used more often
than any other letter. So he decides that the symbol appearing most
often in the code message might stand for the letter e. With that as a
start, he is able to figure out the rest of the message.
But, how did Sherlock Holmes know for sure that e is the most-used
letter in English? How could he have found such a thing out?
Well, here’s an experiment for you to try. It will show you what Holmes
knew. On a piece of paper, write down the letters of the alphabet. Then,
take any page in this book, or any book, and make a record of how many
times each letter is used in the first hundred words on the page. Each
time a letter is used, make a mark next to that letter on your alphabet
list. About nine times out of ten, you’ll find that most of your marks
are next to e.
You can find out all sorts of things in this way. For example, you might
make a list of all the sports you can think of—football, baseball,
basketball, and so on. Then, ask everyone in your class what their
favorite sport is. When they tell you, make a mark next to the name of
that sport on your list. When you’re through, you’ll know which sport is
most popular with your classmates.
Records of this sort are called statistics (stuh TIHS tihks). Statistics
are very useful in many ways. By means of statistics, governments can
find out what sort of crops farmers probably should raise, how many new
homes are likely to be needed in coming years, and many, many other
things.
