An exordium is an address bringing the mind of the hearer into a suitable state to receive the rest of the speech, and that will be effected if it has rendered him well disposed towards the speaker, attentive, and willing to receive information.

An exordium of this nature was the regular procedure.

Your representative makes a speech, the exordium of which is Patriotism, the peroration of which is Star-Spangled Banner, and the central plum of which is your coal mine or iron mill.