Late, great, and much lamented authors of perhaps the weirdest sets of popular math books imaginable. Working from the then-revolutionary theory that
abstract algebra and
number theory can and should be accessible to everyone, they published a half-dozen books on such things as "The Education of T. C. Mits"
non-Euclidean geometry, "The Einstein Theory of Relativity",
relativity (which also contained an appendix explaining the
atomic bomb), and suchlike, written by Lillian in a poem-like ventilated prose, with one phrase on each line, and illustrated with Hugh Grey's
proto-psychedelic doodlings, together with copious editorializing on the ethics of science, racial tolerance, and suchlike.
In entertaining, they're quite successful, in teaching math, they're mostly so. The typography at its best, resembles good callegraphy, or the arrangement of equations on a page, but their whiz-bang listen-up, we're-only-telling-you-once style of exposition often means that you're stuck three-quarters of the way through watching a kaleidoscopic play of symbols, but not having a clue as to what anything means.
On the other hand, they're one of the best ways to get a good math high...