𝐒𝐭𝐞𝐚𝐦𝐩𝐮𝐧𝐤 𝐓𝐞𝐧𝐝𝐞𝐧𝐜𝐢𝐞𝐬 on Twitter
It is interesting :
Stair dust corners are flexible, triangle-shape pieces of brass or nickel that keep dust from accumulating in stair corners. They were introduced near the end of the 19th century as a way to simplify sweeping. https://t.co/qZJwWzImkn