Possibly the most pointless ceiling fans in the wo

Finally, I managed to get this blip.

I have often wondered about these ceiling fans. Why, and who, put them there? The room is huge (it's a library reading room) and is never warm, especially this time of year. If I know I'm going to be working there I have to make sure I layer up as we can't wear our costs - they are afraid that we will steal all the dull books we have to read for our research.

I'm not very good at estimating height, but this ceiling is far, far above our heads. So high is the ceiling that there is room for three balconies/mezzanine(ish) floors to run along each wall. That's almost four floors worth of height.

Which returns me to my question - why put them there? What on earth are they meant to cool down? I've tried to work it out but I give up, I really do.