A third method is to use “cupped” logs. The same saddle and notch is
used at the corners, but the upper log has a concaved channel cut its
entire length, which makes it fit down snugly over the lower log. The
cup may be cut with curved-blade adz or with a heavy gouge. This is more
work but well worth it. Cut each cup to fit its individual lower log,
marking the cup with a pair of dividers to insure a close fit. When you
have a perfect cup (which means rolling the log into position several
times to try its fit) lay a layer of heavy oakum along the lower log,
roll the upper into its final position and spike it down.
The finest method of all is a further refinement of the cupped log
style. The upper log is cupped as above but, instead of a simple notch
at the end, the upper log is cut out exactly to fit down over the lower
tightly, while the lower is not notched at all. Oakum is strung the same
as for other methods and laid in at the corners. In the best work of
this type no oakum should show. Although the pioneers put their cabins
together without nails, they did so because they had no nails to use. To
be safe, spike all logs together with 12-inch spikes—the largest size
made.
Before you get the walls too high, give a thought to windows and doors.
There are two ways of taking care of them. The extravagant way, much
used by our forefathers, was to build with logs to the top line of the
proposed opening and then cut out a hole the required size. An
easier—and less wasteful—way, if you are doing your own work, is to use
short logs, leaving a more or less rectangular opening. Then nail a
couple of straight boards where your frames should come and saw off the
rough projecting log ends as illustrated above.
[Illustration: PLANKS NAILED AS GUIDE FOR CUTTING]