The use of symbols is nothing more than a short cut. In
the world today, everyone is looking for shorter ways of doing
things--so it is not at all peculiar that Radio, even though an
infant industry--has already developed a short cut system of
its own consisting of symbols and signs.
Of course, in studying Radio, your first job will be to get
complete mental pictures of the various parts and actions vital
Fig. 3--Drawing showing floor plan of a house.
to Radio. After you have stored away in your mind these
complete pictures a word, a symbol, or a sign will bring any of these
pictures out of its storehouse into the part of your mind where
you can be conscious of it. As you advance in Radio knowledge,
this process will become automatic and you will be able to picture
Fig. 4--Symbols used for house plans.
in your mind, not only the different Radio parts that are used,
but their actions and the work they do in a Radio receiver.
For example, the word "inductance" may not bring to mind
any particular picture just at this point in the course, but later
on this word will cause a very clear cut picture of a coil to flash
through your mind, and more than that, associated with this
picture will be pictures of electrical actions which result from
