Large arc scale and freezer: what they have in common

1. Step 1. Large arc scale — is part of — Davis quadrant. A scale for small angles.
2. Step 2. Davis quadrant — evolved into — Octant. Reflecting angle gauges.
3. Step 3. Octant — has part — Mirror. Two mirrors.
4. Step 4. Mirror — is part of — Vacuum flask. The silvering reflects heat radiation.
5. Step 5. Vacuum flask — uses — Thermal insulation. Insulation.
6. Step 6. Thermal insulation — is part of — Freezer. Polyurethane foam in the walls.

Open Evothings