[Illustration: Fig 35. Model Stove]
[Illustration: Fig 36. Ordinary Stove]

The oven is the space under and around the back and front sides of the
fire-box. The oven-bottom is not introduced in the diagram, but it is
a horizontal plate between the fire-box and what is represented as the
"flue-plate," which separates the oven from the bottom of the stove.
The top of the oven is the horizontal corrugated plate passing from
the rear edge of the fire-box to the back flues. These are three in
number--the back centre-flue, which is closed to the heat and smoke
coming over the oven from the fire-box by a damper--and the two back
corner-flues. Down these two corner-flues passes the current of hot
air and smoke, having first drawn across the corrugated oven-top. The
arrows show its descent through these flues, from which it obliquely
strikes and passes over the flue-plate, then under it, and then out
through the centre back-flue, which is open at the bottom, up into the
smoke-pipe.

The flue-plate is placed obliquely, to accumulate heat by forcing and
compression; for the back space where the smoke enters from the
corner-flues is largest, and decreases toward the front, so that the
hot current is compressed in a narrow space, between the oven-bottom
and the flue-plate at the place where the bent arrows are seen. Here
again it enters a wider space, under the flue-plate, and proceeds to
another narrow one, between the flue-plate and the bottom of the stove,
and thus is compressed and retained longer than if not impeded by these
various contrivances. The heat and smoke also strike the plate
obliquely, and thus, by reflection from its surface, impart more heat
than if the passage was a horizontal one.