"BobK207" wrote in message

which is 33.0 to 34.3 degrees pretty good for 1930


Actually, is sucks for any time in serious engineering. Yes, it is well
within limits of tolerances for a house being built today, but the reality
is, ancient civilization was able to work to finer tolerances than that.
Aqueducts built 2000 years ago used angles to plot a course through
mountains and they came out in the right spot on the other side.