d L hears from s are close together; this makes what is called
a dot. If R holds K down longer, it makes a longer time between the
clicks for L to hear, and this makes a dash. R, of course, hears his own
sounder, which is making the dots and dashes also.

As soon as R has finished, he closes his switch, E. L then opens his
switch and proceeds to answer. Both E and e should be left closed when
you are through talking.

(Read Sec. 194, 195, and study what is said in App. 9 about the gravity
cell to be used on such a line.)

_212. Telegraph Alphabet._ The letters are represented by combinations
of dots, dashes and spaces. A dot is made by pressing the key down, and
raising it at once; that is, the key is raised as soon as it strikes.
This makes the letter E. The dash is made by pressing down the key, and
allowing the current to pass about as long as it takes to make 3 dots;
this makes the letter T. A long dash for L should take about as long as
for 5 dots. Spaces occur in a letter and between words. To make a dash
you hesitate while the lever of the key is down, to make a space, you
hesitate while the key is up. H is made with 4 dots without hesitation
or space. By putting a space between the dots the letter &, Y or Z is
made according to the position of the space. Notice that letters
containing dashes do not contain spaces. A space is really the opposite
of a dash. The letters C, E, H, I, O, P, R, S, Y, Z, and & are made
entirely of dots or of dots and spaces.

You should notice that several letters are the reverse of others; A is
the reverse of N, B of V, D of U, C of R, Q of X, and Z of &. The
student should study some book upon telegraphy, if he desires to become
expert. Punctuation marks are left out of the alphabet here given, as
boys will find very little use for them.

A _ ___
B ___ _ _ _
C _ _ _
D ___ _ _
E _
F _ ___ _
G ___ ___ _
H _ _ _ _
I _ _
J ___ _ ___ _
K ___ _ ___
L ______
M ___ ___
N ___ _
O _ _
P _ _ _ _ _
Q _ _ ___ _
R _ _ _
S _ _ _
T ___
U _ _ ___
V _ _ _ ___
W _ ___ ___
X _ ___ _ _
Y _ _ _ _
Z _ _ _ _
& _ _ _ _

1 _ ___ ___ _
2 _ _ ___ _ _
3 _ _ _ ___ _
4 _ _ _ _ ___
5 ___ ___ ___
6 _ _ _ _ _ _
7 ___ ___ _ _
8 ___ _ _ _ _
9 ___ _ _ ___
0 ______

CHAPTER XV.

ELECTRIC BELLS AND BUZZERS.

APPARATUS 125.

_213. Electric Buzzer._ Fig. 100. A buzzer is, in construction, very
similar to an electric bell; in fact, you will have a buzzer by removing
the