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According to Maxwell's theory, the speed of light DOES depend on the
speed of the observer:

http://www.amazon.com/Brief-History-Time-Stephen-Hawking/dp/0553380168
Stephen Hawking: "Maxwell's theory predicted that radio or light waves
should travel at a certain fixed speed. But Newton's theory had got
rid of the idea of absolute rest, so if light was supposed to travel
at a fixed speed, one would have to say what that fixed speed was to
be measured relative to. It was therefore suggested that there was a
substance called the "ether" that was present everywhere, even in
"empty" space. Light waves should travel through the ether as sound
waves travel through air, and their speed should therefore be relative
to the ether. Different observers, moving relative to the ether, would
see light coming toward them at different speeds, but light's speed
relative to the ether would remain fixed."

Pentcho Valev wrote:

According to Maxwell's theory, (1) the speed of light is independent
of the speed of the emitter but (2) it does depend on the speed of the
observer:

http://www.pitt.edu/~jdnorton/papers/companion.doc
John Norton: "Einstein's second postulate, the light postulate,
asserts that "light is always propagated in empty space with a
definite velocity c which is independent of the state of motion of the
emitting body." Einstein gave no justification for this postulate in
the introduction to his paper. Its strongest justification came from
Maxwell's electrodynamics. That theory had identified light with waves
propagating in an electromagnetic field and concluded that just one
speed was possible for them in empty space, c = 300,000 km/sec, no
matter what the motion of the emitter."

http://www.futura-sciences.com/fr/doc/t/physique/d/relativite-restreinte-et-naissance-de-lespace-temps_509/c3/221/p5/
"Les équations de Maxwell prévoyaient la propagation de la lumière à
la vitesse de 300.000 km/s par rapport à l'éther. Or, si l'on cherche
à calculer la vitesse de la lumière par rapport à un référentiel qui
est lui-même mobile dans l'éther, on observe que la lumière se propage
avec une vitesse différente..."

http://www.solidarity-us.org/node/58
"Maxwell's theory of electricity and magnetism provides a successful
framework with which to study light. In this theory light is an
electromagnetic wave. Using Maxwell's equations one can compute the
speed of light. One finds that the speed of light is 300,000,000
meters (186,000 miles) per second. The question arises: which inertial
observer is this speed of light relative to? As in the previous
paragraph, two inertial observers traveling relative to each other
should observe DIFFERENT SPEEDS FOR THE SAME LIGHT WAVE."

In 1905 Einstein adopted the former assertion of Maxwell's theory (the
speed of light is independent of the speed of the emitter) and, by
applying the principle of relativity, inferred that the speed of light
is independent of the speed of the observer as well.

Einstein could have adopted the latter assertion of Maxwell's theory
(the speed of light does depend on the speed of the observer). Then,
by applying the principle of relativity, he would have inferred that
the speed of light does depend on the speed of the emitter as well.
This would have been a return to Newton's emission theory of light:

http://www.mfo.de/programme/schedule/2006/08c/OWR_2006_10.pdf
Jean Eisenstaedt: "At the end of the 18th century, a natural extension
of Newton's dynamics to light was developed but immediately forgotten.
A body of works completed the Principia with a relativistic optics of
moving bodies, the discovery of the Doppler-Fizeau effect some sixty
years before Doppler, and many other effects and ideas which represent
a fascinating preamble to Einstein relativities. It was simply
supposed that 'a body-light', as Newton named it, was subject to the
whole dynamics of the Principia in much the same way as were material
particles; thus it was subject to the Galilean relativity and its
velocity was supposed to be variable. Of course it was subject to the
short range 'refringent' force of the corpuscular theory of light --
which is part of the Principia-- but also to the long range force of
gravitation which induces Newton's theory of gravitation. The fact
that the 'mass' of a corpuscle of light was not known did not
constitute a problem since it does not appear in the Newtonian (or
Einsteinian) equations of motion. It was precisely what John Michell
(1724-1793), Robert Blair (1748-1828), Johann G. von Soldner
(1776-1833) and François Arago (1786-1853) were to do at the end of
the 18th century and the beginning the 19th century in the context of
Newton's dynamics. Actually this 'completed' Newtonian theory of light
and material corpuscle seems to have been implicitly accepted at the
time. In such a Newtonian context, not only Soldner's calculation of
the deviation of light in a gravitational field was understood, but
also dark bodies (cousins of black holes). A natural (Galilean and
thus relativistic) optics of moving bodies was also developed which
easily explained aberration and implied as well the essence of what we
call today the Doppler effect. Moreover, at the same time the
structure of -- but also the questions raised by-- the Michelson
experiment was understood. Most of this corpus has long been
forgotten. The Michell-Blair-Arago effect, prior to Doppler's effect,
is entirely unknown to physicists and historians. As to the influence
of gravitation on light, the story was very superficially known but
had never been studied in any detail. Moreover, the existence of a
theory dealing with light, relativity and gravitation, embedded in
Newton's Principia was completely ignored by physicists and by
historians as well. But it was a simple and natural way to deal with
the question of light, relativity (and gravitation) in a Newtonian
context."

http://ustl1.univ-lille1.fr/culture/publication/lna/detail/lna40/pgs/4_5.pdf
Jean Eisenstaedt: "Même s'il était conscient de l'intérêt de la
théorie de l'émission, Einstein n'a pas pris le chemin, totalement
oublié, de Michell, de Blair, des Principia en somme. Le contexte de
découverte de la relativité ignorera le XVIIIème siècle et ses racines
historiques plongent au coeur du XIXème siècle. Arago, Fresnel,
Fizeau, Maxwell, Mascart, Michelson, Poincaré, Lorentz en furent les
principaux acteurs et l'optique ondulatoire le cadre dans lequel ces
questions sont posées. Pourtant, au plan des structures physiques,
l'optique relativiste des corps en mouvement de cette fin du XVIIIème
est infiniment plus intéressante - et plus utile pédagogiquement - que
le long cheminement qu'a imposé l'éther."

Pentcho Valev
pvalev@yahoo.com