How beautifully is the wisdom of God developed in shaping out and
moulding shells! and especially in the particular value of the constant
angle which the spiral of each species of shell affects,--a value
connected by a necessary relation with the economy of the material
of each, and with its stability and the conditions of its buoyancy.
Thus the shell of the _Nautilus Pompilius_ has, hydrostatically, an
A-statical surface. If placed with any portion of its surface upon the
water, it will immediately turn over towards its smaller end, and rest
only on its mouth. Those conversant with the theory of floating bodies
will recognise in this an interesting property.--_Ibid._