Also possible is filling some of the buggy frame's usually hollow tubes with a dense substance such as lead.
They were lined with a dense, hard, metallic substance that glowed in the dark: it was called Heechee metal.
The dangers of oil or fat fires (generally flammable substances less dense than water) are well known in industrial processes.
This dense substance grants him superhuman strength, weight, stamina, and healing.
The golem is pitted where bullets have stopped in its dense substance.
Lead is an example of a very dense substance: a small volume contains a large mass (and therefore weighs a lot for its volume).
In a dense substance, each free electron has less available distance to fall before bumping into the next atom it must ionize.
It is a dense substance, with a specific gravity between 5.6 and 6.0 - at least 1.6 times that of diamond.
As he waded through it, the dense substance floated up knee-high before settling heavily back down.
The ring floor, a substance dense enough to stop 40 percent of neutrinos, and presumably very rigid.