Like most scientists, Zwicky published mainly technical research papers in journals and seminar and colloquia complilations, and not many books. Only this one, in 1955. It wasn't until fifty years later, when a biography of him was published, that I found out only 2,000 copies were printed. One wonders how many are still around.

Mine came from the Discards box ("Free - Take Whatever You Want") outside the university physics library in the late-1970s when the book was 20+ years old. I think it was the only time I stopped and looked to see what might be in the box, because I was only an undergrad (prob. a junior) and all the titles were way over my head. Many were those cheaply printed soft-cover colloquia compilations, six or ten year old and presumed to be no longer current. Many were also as large as a phone book, and I remember thinking it incredible that there could be so much on such an arcane or obscure topic as the title gave a hint of, a consequence of how specialized science had become.

So, after rifling through the box, I noticed Zwicky's slim, relatively small book. I'd taken some astronomy courses but had no idea what morphological astronomy might be about. Flipping through it's pages I saw it had photos of clusters of galaxies, which I was interested in but hadn't had much of in any course yet, so it was an easy choice to slip it in the backpack and walk away with it. It looked like it contained "real" astronomy -- as opposed to course-work astronomy. Like I said, it's not a very big book.

I put it on the shelf and probably didn't get around to looking at it for six months or almost a year. With science changing so fast I didn't think it would be very current, that a lot of what was in it would now be considered wrong. So it was awhile before I read it. By then I'd had a course in galaxies and cosmology, so I figured I might be able to read it and sort out what had changed in the interim. Usually the measurements turn out to be correct while it's the interpretations that change.