Isaac Newton and the Wigton floods

I was fortunate to be able to go to Isaac Newton's house at Woolsthorpe near Grantham at last. His most famous work is the Principia Mathematica. What I didn't know was that the middle section of the book was about fluid mechanics. And the pictures below show a body of fluid in Wigton today...

Apparently Newton wrote about the effects of friction and viscosity on the flow of fluids. At the edge of the river, friction from the bank acts on the water, slowing it down. Then he modeled the water as moving in layers, each one affected by the pull of the one outside it. This pull of a liquid is called its viscosity. Hence the fastest water flows in the middle. So important was the work that they now talk about Newtonian fluids. I used to know about these things so I need to re-read it.