Retractable Ballpoint Pens, Solar Salt, Tubas

תקציר הפרק

Injection-moulded pen bodies are fitted with ink refills, ballpoint tips, springs and retracting mechanisms. Salt water is concentrated in large evaporation ponds until crystals can be harvested and refined, while sheets and tubes of brass are shaped, joined and polished into the long air passages and broad bell of a tuba.