Re: gauge railway workshop to yard

"Richard Smith"  wrote in message news:m1y17d5ju9.fsf@void.com...
This is driven by my wanting to actually experience the realities of
mineral processing.
Start with a heap of "rocks" and end up with some metallic minerals.
I'm getting better at spotting things.
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Small ore samples can be analyzed and smelted to metal with little more than a candle, jet of breath air and charcoal.
https://www.gutenberg.org/files/32974/32974-h/32974-h.htm
https://www.911metallurgist.com/blog/blowpipe-analysis-for-testing-minerals
To blow continuously you close the back of your throat and blow with your cheeks while inhaling rapidly through your nose. The platinum wire ($1.25 in 1965) and blowpipe were on the bookstore purchase list for freshman university chemistry students. Perhaps they still are. Cobalt glass blocks the intense yellow of Sodium so you can see what else is there.
I also used the blowpipe and a candle to make tiny glass animals for my girlfriend. Fragments of the broken milk glass lamp globe in the dorm bathroom became speckled like a fawn when overheated.
Wet chemical analysis is somewhat more definitive and thorough, but it requires chemicals no longer easily available, and hazardous waste disposal. The simpler Qualitative analysis shows what's there, the more involved Quantitative analysis measures how much, on a sensitive weighing scale.
This very nice sighting compass was required for the agricultural students.
https://www.suunto.com/Products/Compasses/Suunto-KB-14/Suunto-KB-14360R1/
I bought one at the asking price from a student who didn't expect to ever need it again. Looking into the end you see the magnified degree scale and a vertical reference line that can be made to extend up over the distant target as well. The liquid damping appeared good enough for marine use on the calm day I tried it.