3. Is permanent, when we want to keep the information.

4. Is erasable, when we want to remove information.

5. Is versatile, holds easily any kind of information, and allows operations to be done easily.

The amount of human effort needed to handle information correctly depends very much on the properties of the physical equipment expressing the information, although the laws of correct reasoning are independent of the equipment. For example, the great difficulty with spoken sounds as physical equipment for handling information is the trouble of storing them. The technique for doing so was mastered only about 1877 when Thomas A. Edison made the first phonograph. Even with this advance, no one can glance at a soundtrack and tell quickly what sounds are stored there; only by turning back the machine and listening to a groove can we determine this. It was not possible for the men of 2000 b.c. to wait thousands of years for the storing of spoken sounds. The problem of storing information was accordingly taken to other types of physical equipment.

PHYSICAL EQUIPMENT FOR
HANDLING INFORMATION

No.Physical
Objects		Arranged
in or on		Operated or
Produced by		Low
Cost?		Little
Space?		Perma-
nent?		Eras-
able?		Vers-
atile?
(1)(2)(3)(4)(5)(6)(7)(8)(9)
Mind
1.Nerve
cells		Human
brain		Body✕✓✓✓✓✓✓
Sounds
2.SoundsAirVoice✓✓✓✓✕✕✓✓✓✓
3.Sound-
tracks		Wax
cylinders,
phonograph
records		Machines
and
motors		✓✓✓✓✕✓✓
Sights
4.MarksSandStick✓✕✓✓✓✕
5.Colored
painting
canvases,
etc.		Cave
walls,		Paintbrush
and paints		✕✕✓✕✕✕
6.Marks,
inscript-
ions		Clay,
stone		Stylus,
chisel		✕✕✓✓✓✕✕✓
7.MarksSlateChalk✓✕✓✓✓✓
8.Marks
parchment,
etc.		Paper,
and ink,
pencil		Pen✓✓✓✓✕✓✓
9.Letters,
etc.		Paper
books
etc.		Printing
press,
movable
type,
motor,
and hands		✓✓✓✓✓✓✕✕✓✓
10.Photo-
graphs		Film,
prints,
etc.		Camera✓✓✓✓✕✕✓✓
11.Letters,
etc.		Paper,
mimeograph
stencil,
etc.		Typewriter
and
fingers		✓✓✓✓✕✓✓
Body
12.GesturesSpaceBody✓✕✕✕✓✓✕✕
13.FingersHandsBody✕✕✕✕✓✓✕✕
Objects
14.PebblesSlabHands✓✓✓✓✓✕✕
15.KnotsStringHands✓✓✓✓✓✕✕
16.Tallies,
notches		StickKnife✓✓✓✓✓✕✕✕✕
17.BeadsRods in
a frame,
abacus		Hands✓✓✓✓✓✕✕
18.Ruled
lines,
pointers		Rulers,
scales,
dials		Hands,
pressure,
etc.		✓✓✓✓✓
Machines
19.Counter
wheels,
gears,
keys,
lights,
etc.		Desk
calculating
machines,
fire-control
instruments,
etc.		Motor
and
hands		✓✓✓✓✓✓
20.Punched
cards
and
paper
tape		Punch card
machinery,
teletype,
etc.		Motor
and
input
instructions		✓✓✓✓✓✕✓✓
21.RelaysDial
telephone,
other
machinery		Motor
and
input
instructions		✕✓✓✓✓✓✓
22.Elect-
ronic
tubes		MachineryMotor
and
input
instructions		✓✓✓✓✓✓✓
23.Magnetic
surfaces:
wire,
tape,
discs		MachineryMotor
and
input
instructions		✓✓✓✓✓✓✓✓✓✓
24.Delay
lines:
electric,
acoustic		MachineryMotor
and
input
instructions		✕✓✕✓✓✓✓
25.Electro-
static
storage
tubes		MachineryMotor
and
input
instructions		✕✓✓✕✓✓✓✓

What are the types of physical equipment for handling information, and which are the good ones? In the table on [pp. 16-17] is a rough list of 25 types of physical equipment for handling information. ✓✓ means “yes, very;” ✓ means “yes, adequately;” ✕ means “not generally;” ✕✕ means “not at all.”

For example, our fingers ([see No. 13]) as a device for handling information are very expensive for most cases. They take up a good deal of space. Certainly they are very temporary storage; any information they may express is very erasable; and what we can express with them alone is very limited. Yet, with a typewriter ([see No. 11]), our fingers become versatile and efficient. In fact, our fingers can make 4 strokes a second; we can select any one of about 38 keys; and, since each key is equivalent to 5 or 6 units of information, the effective speed of our fingers may be about 800 units of information a second.

LANGUAGES OF PHYSICAL OBJECTS