Spiral with orientation mathematica

eqn = {(a + b*theta)*Cos[theta], (a + b*theta)*Sin[theta]};
deqn = D[eqn, theta]
Graphics[Table[
  Translate[
    Rotate[Rectangle[{-0.1, -0.5}, {0.1, 0.5}],
     ArcTan[deqn[[1]], deqn[[2]]]], eqn] /. {a -> 1, b -> 1,
    theta -> t}, {t, .2, 10, 0.2}]
 ]
(* NOTES: ArcTan is diefferently defined in mathematica than in c and c++ for example *)