lar details of such a building (such as windows, doors, stairways,
etc.) are here shown, as they would only tend to complicate an
explanation.

It will be noted that there are really two sets of molds, an inside and
an outside set, leaving a space between them throughout. Although not
shown in the sketch, there is in practice a number of bolts passing
through these two sets of molds at various places to hold them together
in their relative positions. In the open space between the molds there
are placed steel rods for the purpose of reinforcement; while all
through the entire structure provision is made for water and steam
pipes, gas-pipes and electric-light wires being placed in appropriate
positions as the molds are assembled.

At the centre of the roof there will be noted a funnel-shaped opening.
Into this there is delivered by the endless chain of buckets shown on
the left a continuous stream of a special free-flowing concrete mixture.
This mixture descends by gravity, and gradually fills the entire
space between the two sets of molds. The delivery of the material--or
"pouring," as it is called--is continued until every part of the
space is filled and the mixture is even with the tip of the roof,
thus completing the pouring, or casting, of the house. In a few days
afterward the concrete will have hardened sufficiently to allow the
molds to be taken away leaving an entire house, from cellar floor to the
peak of the roof, complete in all its parts, even to mantels and picture
molding, and requiring only windows and doors, plumbing, heating, and
lighting fixtures to make it ready for habitation.

In the above sketch the concrete mixers, A, B, are driven by the
electric motor, C. As the material is mixed it descends into the tank,
D, and flows through a trough into a lower tank, E, in which it is
constantly stirred, and from which it is taken by the endless chain
of buckets and dumped into the funnel-shaped opening at the top of the
molds, as above described.

The molds are made of cast-iron in sections of such size and weight as
will be most convenient for handling, mostly in pieces not exceeding two
by four feet in rectangular dimensions. The subjoined sketch shows
an exterior view of several of these molds as they appear when bolted
together, the intersecting central portions representing ribs, which are
included as part of the casting for purposes of strength and rigidity.

The molds represented above are those