We will construct differential forms on the embedding spaces using
configuration space integral associated with 1-loop graphs. In particular, for
any pair n, j of positive integers with n-j>=2, we show that some linear
combination of such differential forms together with some correction terms
coming from a 1-parameter family of immersions gives a closed form on the space
fEmb(R^j,R^n) of embeddings with 1-parameter families of immersions to the
trivial. We also show that the closed forms obtained detect nontrivial elements
of the real homology of the embedding space fEmb(R^j,R^n).