1 dp= 0,   1 dp= 0,   1 dp= 1,
ρ dxρ dyρ dz

(1)

P = ∫ dp/ρ = z + a constant.

(2)

When the density ρ is uniform, this becomes, as before in (2) § 9

p = ρz + p0.

(3)

Suppose the density ρ varies as some nth power of the depth below O, then

dp/dz = ρ = μzn

(4)