Let us say that the cabinet now made is a success and the
manufacturer decides to make a number of cabinets like it.
Several cabinet makers will be assigned to the job and each one
must have his own diagrams. It takes considerable time to
make a diagram and to have duplicates made by redrawing them
would mean time wasted. Time is valuable to the manufacturer
--so be has the diagram duplicated by the blueprint process
which permits any number of copies to be made from a single
original. Then the blueprint diagrams are passed out to the
individual cabinet makers and they can get to work on the new
cabinets immediately.
RADIO SYMBOLS--RADIO DIAGRAMS
The contractor who builds houses continually uses blueprints.
If we were to examine one of these diagrams it might
mean very little to us. But to the builder it means everything--
it is in a language he understands-knowledge of which he shares
with the architect who made the original drawing. By means of
this diagram, the builder can get a mental picture of what the
architect had in his mind without the exchange of a single word.
Figure 3 shows just one of a set of drawings which the
builder uses. It is a diagram showing the lower floor plan of a
house. The builder, with only this to go on, can visualize the
completed rooms on the first floor. He knows where the windows
and the doors will be; where the stairs leading to the second
floor will be; where the fireplace in the living room is going to
be, etc.
How can he know all this? Because different combinations
of lines bring to his mind pictures of the things they represent.
Lines arranged as in Fig. 4 a represent a door, as in Fig. 4 b, a
window; as in Fig. 4t, the stairs; as in Fig. 4 d, a fireplace.
These are symbols which stand for but do not actually picture
objects.
Why symbols are used in diagrams of this sort is perfectly
clear. If every detail were actually pictured, the drawings would
be exceedingly complicated. But it isn't at all necessary to
picture each detail in a layout diagram--everybody knows what a
door is, everybody knows what a window is. So, to save time
and trouble, architects and builders got together and decided
upon symbols for objects--and now when a builder sees one of
these symbols, a mental picture of the object it represents
instantly flashes through his mind.
