OF DISTRIBUTING THE PRESSURE ABOVE AN ARCH.
Next to giving the segments of the circle equal weight it is necessary to load them equally, or you will fall into the same defect as before.
WHERE AN ARCH BREAKS.
An arch breaks at the part which lies below half way from the centre.
SECOND RUPTURE OF THE ARCH.
If the excess of weight be placed in the middle of the arch at the point a, that weight tends to fall towards b, and the arch breaks at 2/3 of its height at c e; and g e is as many times stronger than e a, as m o goes into m n.
ON ANOTHER CAUSE OF RUIN.
The arch will likewise give way under a transversal thrust, for when the charge is not thrown directly on the foot of the arch, the arch lasts but a short time.
780.