tre to centre. The distance may
be increased to a foot, Or even more if weight-saving is an object.

CONSTRUCTION.

Preparing the Sides.--These are cut to exactly the same length, which we
will assume to be 11 feet 6 inches, planed quite smooth and rounded off
slightly at the corners to make handling comfortable. Before marking them
for the rungs it is important that they shall be so arranged that both
incline equally towards a centre line.

Stretch a string tightly three inches above the ground, and lay the sides
of the ladder on edge to right and left of it, their ends level. Adjust the
bottom ends 8-1/2, the top ends 6-1/2 inches from the string, measuring
from the outside. Tack on cross pieces to prevent shifting, and then,
starting from the bottom, make a mark every 10 inches on the outside
corners, to show the position of the tops of the rungs. A piece of the wood
to be used for making the rungs of is laid up to the pairs of marks in
turn, and lines are drawn on both sides of it.

Cutting the Notches.--The work of marking the ends of the notches will be
quickened, and rendered more accurate, if a template (Fig. 10) is cut out
of tin. The side AC is 3/8 to 1/2 inch deep. Apply the template to both
faces of the side in turn, with its corner A at the line below the rung,
and DE flush with the upper corner. When all the notches have been marked
cut down the AC line of each with a tenon saw, and chisel along BC till the
wedge-shaped chip is removed. Finish off every notch as neatly as possible,
so that the rungs may make close contact and keep water out.

Preparing the Rungs.--Lay a piece of rung batten across the lowest
notches, the end overhanging the side by a quarter of an inch or so to
allow for the taper of the ladder, and draw your pencil along the angles
which it makes with the sides. Mark the positions of the nail holes. Cut
off the rung at the cross lines; drill the four nail holes on the skew, as
shown in Fig. 10; and round off all the corners. The other rungs are
treated in the same manner, and the sides are then separated, for the
inside top corner and both back corners, which will be handled most, to be
well rounded off and rubbed smooth with glass paper.

Assembling.--Before putting the parts together give them a coating of
paint, as the contact surfaces will not be accessible to the brush
afterwards. When the paint has dried, lay the sides out as before, and nail
on the rungs with 3-inch nails. T