## The Need for Speed

The promise that the ENIAC offered the army was one of speed. Despite advances
in mechanical calculators, such as the differential analyzer, the Army's
need for number-crunching far exceeded the ability of any calculating machine
of the day.

The Army needed many new firing tables. A firing table was a small booklet
attached to a gun that allowed the soldiers to determine the correct firing
angle for a given distance. These tables took into account many variables,
such as wind, temperature, and even the type of ground under the gun.

The old ways were very slow. Each trajectory took 12 hours to calculate
with a mechanical desk calculator.

The ENIAC was very fast. Instead of taking 12 hours, the ENIAC could compute
the trajectory of a shell in just 30 seconds.

Here's an example of the operation of the ENIAC.

Continue on to The Calculation...

Back to the ENIAC at Penn...