Planimeter

device · 1814 · Industrial Revolution

An instrument for measuring areas.

What it is made of

• Wheel — has part. A measuring wheel computes the area.
• Pole arm — has part. A lever with a fixed pole.
• Tracer arm — has part. A stylus traces the outline.
• Measuring wheel — has part. A counting wheel integrates the area.

Principles and materials it uses

• Calculus — uses. Mechanical integration.
• Brass — is made of. A planimeter is brass.

Where it is used

• Differential analyser — is part of. Wheel-and-disc integrators.

Take Planimeter apart

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