Logarithm and rope: what they have in common
- Step 1. Logarithm — is used in — Slide rule. The scales are logarithmic: multiplication becomes adding lengths.
- Step 2. Slide rule — is a kind of — Computing device. An analogue calculator.
- Step 3. Computing device — includes — Tide-predicting machine. An analogue calculator.
- Step 4. Tide-predicting machine — has part — Pulley. Pulleys add up the harmonics.
- Step 5. Pulley — uses — Rope. A rope runs over the pulley.