the relation between profits and sales of other dealers we would
get other equations. So this could not rightly be called a
formula.
Our last equation, "Dr. Ohm's," however, is a formula.
It has been proven true thousands of times--it expresses a law
of electricity-and laws expressed in the form of equations, are
formulas.
These represent the finer, more accurate "tools" of the
Radio-Trician, Don't get the idea that it will be difficult to learn
how to use them. The hard work has all been done. It takes
a great deal of mathematical skill to work out and prove
a formula, but after that has been done, it is like a screw-driver,
an automobile, or a Radio set--anyone with the proper knowledge
can use it. A man can be a good automobile driver without
knowing how to build an automobile. Anyone can use a saw,
and yet the inventor of the saw may have spent his whole life
working out just this one idea.
Throughout your Radio studies you will be shown a number
of formulas, simply because they are part of the Radio-Trician's
equipment. Study them with the idea of learning how
to use them--not of learning how to make them.
A list of the exact quantities of everything used in making
good old-fashioned ginger bread is, strictly speaking, a formula
even though we do call it a recipe. We deal with formulas all
day long without realizing it. We don't have to be afraid of
them--in fact, When you want to design Radio frequency coils
or grid bias resistances (these are all things you will become
very familiar with in later lessons), formulas will be your
closest friends.
The partial list of Radio abbreviations shown in Table 10 is
included to make our book complete--for abbreviations are merely
short cuts and so must be considered part of the specialized
Radio-Trician's language. It isn't necessary to attempt to
memorize this table--use it as you need it for reference. A more
complete list of abbreviations is given in "The Radio-Tricians'
Dictionary."
