The plastic concrete filling or beton which the shells are made to contain may be deposited between the slabs when any number of courses (according to convenience) have been built up, and when set practically forms with the solid work introduced a monolith, to which the face slabs are securely keyed.

This I found to belong to a man named Meachem, who had an octagon concrete house built on one side of the opening.

The way in which type concretes truth is sufficiently plain; but it may be useful, with respect to plot, to draw out more in detail the analogy which has been said to exist between it and an illustrative scientific experiment.