new #Primitive-Technology today, with a bottlenecked 2.5-m-tall “natural draft furnace” for smelting; 250mm inside diameter, 125mm inside chimney diameter. With four tuyeres pointing down into a pit, it has a draft velocity at the chimney of some ten meters per second: at 32fps the flame is about one meter tall and about three frames long. Late in the process he discovers that he can prefabricate horizontal slices to add to the chimney and dry them before adding. It looks like a blowtorch pointed at the sky! He had to lash up a ladder to finish the smokestack. He says it’s only 2.5m tall (where the chimney would wobble if bumped) but it looks taller than 3 m to me. For smelting he first built a charcoal mound with a new “triangular log-cabin chimney” approach to, I guess, cut down on the latency, allowing him to light the mound in the bottom center, but he still had to wait until the next day to break it open. There was a lot of overburning. He says iron oxide bacteria bloomed in the wet season when the waterlogged ground “leaches out iron”. The smelt completely failed.
#news conference with Zelenskyy and Macron: #Ukraine will have troops from 20 countries, apparently including France, as a security guarantee against Russia — “as soon as there is a ceasefire”. 35 countries in the “Coalition of the Willing”/“Coalition des Volontaires”, 26 with already-formalized contributions. #politics