Additional testimony to these laws of economical use to space and time, I remember once that the library has rented its space to a butterfly specimen exhibition. taking place in the main exhibition hall of the library. A lady living upstairs gave me an extra ticket from her young son. The guard wouldn't let me in, gesturing that, the ticket was for even younger children in kindergarten. I did not make it to the exhibition and saw facilities carrying boxes of butterfly specimen, they were dismantling the exhibition.