se above the
ground, the firmer it will be. The foundations of the walls must be laid at
least two feet lower than the bottom of the cellar, unless the foundation
be firm rock; and care must be taken to leave a small drain into the pit
quite through the lowest part of the foundation of the lever wall, to let
off any water that may be spilt in the engine house, or may naturally come
into the cellar. If the foundation at that depth does not prove good, you
must either go down to a better if in your reach, or make it good by a
platform of wood or piles, or both.

423. _Q._--These directions refer to the foundations?

_A._.--Yes; but I will now proceed to the other parts. Within the house,
low walls must be built to carry the cylinder beams, so as to leave
sufficient room to come at the holding down bolts, and the ends of these
beams must also be lodged in the wall The lever wall must be built in the
firmest manner, and run solid, course by course, with thin lime mortar,
care being taken that the lime has not been long slaked. If the house be
built of stone, let the stones be large and long, and let many headers be
laid through the wall: it should also be a rule, that every stone be laid
on the broadest bed it has, and never set on its edge. A course or two
above the lintel of the door that leads to the condenser, build into the
wall two parallel flat thin bars of iron equally distant from each other,
and from the outside and inside of the wall, and reaching the whole breadth
of the lever wall. About a foot higher in the wall, lay at every four feet
of the breadth of the front, other bars of the same kind at right angles to
the former course, and reaching quite through the thickness of the wall;
and at each front corner lay a long bar in the middle of the side walls,
and reaching quite through the front wall; if these bars are 10 feet or 12
feet long it will be sufficient. When the house is built up nearly to the
bottom of the opening under the great beam another double course of bars is
to be built in, as has been directed. At the level of the upper cylinder
beams, holes must be left in the walls for their ends, with room to move
them laterally, so that the cylinder may be got in; and smaller holes must
be left quite through the walls for the introduction of iron bars, which
being firmly fastened to the cylinder beams at one end, and screwed at the
other or outer end, will serve, by their going through both the front and
b