  We present a new invariant, called slope, of a colored link in an integral
homology sphere and use this invariant to complete the signature formula for
the splice of two links. We develop a number of ways of computing the slope and
a few vanishing results. Besides, we discuss the concordance invariance of the
slope and establish its close relation to the Conway polynomials, on the one
hand, and to the Kojima--Yamasaki $\eta$-function (in the univariate case) and
Cochran invariants, on the other hand.
