mercalli scale: a scale formerly used to describe the magnitude of an earthquake; an earthquake detected only by seismographs is a I and an earthquake that destroys all buildings is a XII
scale: an ordered reference standard
bond: a certificate of debt (usually interest-bearing or discounted) that is issued by a government or corporation in order to raise money; the issuer is required to pay a fixed sum annually until maturity and then a fixed sum to repay the principal