slightly wedge shaped bricks/stones used to build an arch

ie, child sacrifice was one of the measures once taken to keep bridges from falling down

the basic condition for the safety of masonry is that the thrust line is kept within the middle third of a wall or column

building out masonry step-wise from each side until the stones meet in the middle (precursor to an arch)

that’s why it softens

a line passing down the wall of a building from the top to bottom which defines the position at which vertical thrust can be thought to act on each joint

distortion in material over time

when people are exposed to prolonged, strong vibrations (such as from using chainsaws), their arteries can elongate

so one could sail up the Nile, then drift back down with the current

the horizontal tension member or tie-bar across the bottom of a truss

french for “built-in”

beam one end of which is ‘built in’ to some rigid support

shearing load / area

a measure of the tendency for one part of a solid to slide past the neighboring part

angle through which material is distorted as a result of shear stress (in radians)

stiffness of a material in shear (shear stress / shear strain). equivalent of Young’s modulus.

different in different directions (aka aelotropic)

same in all directions (from greek)

English longbows were made from Spanish Yew, which grows in the Medit. But yew bows are unrealiable above 35 C.

area under stress/strain curve (¹⁄₂ * s * e for Hookean materials)