In my world, there is a species of underwater people. They are a mix of the creatures from Luca, and the creature from the Black Lagoon. At some point, when their technology progresses, they learn about the Industrial Revolution from above. Wanting to catch up with their land competitors and political enemies, they decide to try and industrialize their societies. Their technological state is similar to that of the 17th-18th centuries. How could they industrialize with their conditions?

Notes to mention:

  1. While they do not have fire, there is hot magma produced from volcanoes.
  • While the magma may not be hot for metals, the magic system allows for the heat to be concentrated, making it extremely hot in certain sections, such as the interiors of a blast furnace.
  1. They use animals such as whales and dolphins for riding
  2. They already have good agriculture, growing seaweed as the cash crop and having sea mammals as livestock.
  3. In the area where it is happening, there is no political unrest.
  • $\begingroup$ Lava coming out of volcanos can be up to 1250C. Iron melts at 1538C. So the underwater people can't work iron, which puts their tech level way behind the ancient civilisations, let alone the Renaissance. This assumes they can even approach the underwater lava flows that either a) cool off below useful temperature due to the mass of water or b) are surrounded by high temperature water vapour. So more info needed on their existing tech - "agriculture" is a prehistoric invention - and what "industrialise" means in terms of objectives. $\endgroup$ Aug 31, 2022 at 3:50
  • 1
    $\begingroup$ The accepted answer in this related question (worldbuilding.stackexchange.com/questions/1452/…) is very interesting. $\endgroup$
    – KC Wong
    Aug 31, 2022 at 4:38
  • 1
    $\begingroup$ I think you should really do some search among the existing questions before posting yours. $\endgroup$
    – L.Dutch
    Aug 31, 2022 at 4:41
  • $\begingroup$ The difficulty in obtaining metals is not fundamentally one of temperature. Hydrogen has a high electronegativity and surrounds the environment in the form of H20. So it won't be possible to extract most metals from their oxides under water. You would have to rely on things like gold. sciencenotes.org/printable-periodic-table-electronegativity $\endgroup$
    – Slarty
    Aug 31, 2022 at 7:31
  • $\begingroup$ Boris Stern had written a sci-fi book "Ice shell" (or eggshell - translation is mine, so can be off) depicting an industrializing underwater society on Europa, ice covered moon of Jupiter, which tried to explore the universe outside the crust of ice. Their choice of heat source for metallurgy was friction. The book is in russian only though. $\endgroup$
    – ZuOverture
    Aug 31, 2022 at 14:59