  The phenomenological consequences of unification of Einstein gravity and
electromagnetism in an early phase of a Machian universe with a very small and
uniform electrical charge density $\rho_q$ are explored. A form of the Strong
Equivalence Principle for unified electrogravity is first formulated, and it
immediately leads to (i) the empirical Schuster-Blackett law relating the
magnetic moments and angular momenta of neutral astronomical bodies, (ii) an
analogous relation between the linear acceleration of neutral massive bodies
and associated electric fields, (iii) gravitational lensing in excess of
Einstein gravity, and, with the additional assumption of scaling, to (iv) the
Wesson relation between the angular momentum and the square of the mass of
astronomical bodies. Incorporation of Sciama's version of Mach's principle
leads to a new post-Newtonian dynamics (in the weak field limit of gravity
alone without electromagnetism) that predicts flat rotation curves of galaxies
without the need of dark matter haloes. Finally, it is shown that the unified
theory with a broken symmetry predicts a flat expanding universe with a
cosmological term intimately related to electrogravity unification, and can
explain WMAP data with a single free parameter. WMAP data require $\rho_q
=6.1\times 10^{-43}$ C/cc which is too small to be detected at
