Crossword-Solution: INCOMPRESSIBLE 14 letters, 7 clues 🏆 scrabble score: 22

When I wanted to find out the necessary increase of weight required to sink the _Nautilus_, I had only to calculate the reduction of volume that sea-water acquires according to the depth.” “That is evident.” “Now, if water is not absolutely incompressible, it is at least capable of very slight compression.

But in 1858 the equations of motion of an incompressible frictionless fluid were first successfully solved by Helmholtz, and among other things he proved that, though vortex-motion could not be originated in such a fluid, yet supposing it once to exist, it would exist to all eternity and could not be diminished by any mechanical action whatever.

Why does not the ether, when set aquiver with the vibration which gives us the sensation we call light, have produced in its substance subordinate quivers, setting out at right angles from the path of the original quiver? Such perpendicular vibrations seem not to exist, else we might see around a corner; how explain their absence? The physicist could think of but one way: they must assume that the ether is incompressible.

Let us suppose then that our ideal star also radiates and shrinks, but let the process proceed so slowly that any internal currents generated in the liquid by the cooling are annulled so quickly by fluid friction as to be insignificant; further let the liquid always remain at any instant incompressible and homogeneous.

All that we are concerned with is that, as time passes, the liquid star shrinks, rotates in one piece as if it were solid, and remains incompressible and homogeneous.