Nowadays, Universities get money by charging students, owning property, and making money from research. It's not uncommon for parents of students to contribute large sums of money for new buildings or trusts, or for alumni to donate (I get asked, but I don't donate). I should imagine that the big two get most of their money from property, since when I lived in Cambridge someone told me the Uni owns almost everything between Cambridge & London.
Individual members of staff get paid a salary, but don't get a cut of the riches. But now they'll let anyone work in a Uni, provided they have the qualifications (standards are slipping), whereas beforehand only rich dudes did, so their chairs may well have been honorary or emeritus based on research output (they give you an office but no money).
So, um, I don't know. Fees, rents, trusts, is my best bet.
What's up with this glass? Excuse me? Excuse me? This is my glass? I don't think so. My glass was full! And it was a bigger glass!