Shadow vane and bellows: what they have in common

1. Step 1. Shadow vane — is part of — Davis quadrant. It casts the Sun’s shadow onto the slit.
2. Step 2. Davis quadrant — evolved from — Jacob’s staff. Davis spared the navigator from looking at the Sun.
3. Step 3. Jacob’s staff — works like — Quadrant. Two angle gauges for measuring the altitude of celestial bodies.
4. Step 4. Quadrant — is made of — Bronze. Quadrants are bronze or wooden.
5. Step 5. Bronze — is material for — Pipe organ. The pipes of the hydraulis were bronze.
6. Step 6. Pipe organ — has part — Bellows. Bellows supply the air.

Open Evothings