I used to know nothing about Lord Kelvin except he said things like "It seems, therefore, on the whole most probable that the sun has not illuminated the earth for 100,000,000 years, and almost certain that he has not done so for 500,000,000 years"[1] and allegedly "everything which can be discovered, has been discovered"; until last year's Veritasium video on YouTube[2] about analog computers, and learned he invented tide-predicting analog computers to "substitute brass for brains" and add sinusoidal curves, and a mechanical integrator to separate out individual sinusoidal frequencies from the sum.

[1] https://zapatopi.net/kelvin/papers/on_the_age_of_the_suns_he...

[2] https://www.youtube.com/watch?v=IgF3OX8nT0w from about 3 minutes.