"Rubber" Houser
"Rubber" Houser was a student at Unseen University at the same time as the Bursar. He was described as "a reflective sort of boy".
In an attempt to circumvent the University's punishment of writing out lines, Houser scrounged some bits of wood and stripped a mattress of its springs to design the Graphical Device. This device began as a four-line writing machine, but eventually became capable of writing sixteen and thirty-two lines at once. Houser's invention became extremely popular- students would break rules so they could have a go at using the Graphical Device (for threepence to use it and a penny to help wind it up). Eventually, Houser's experiments came to an end when someone opened a wrong door and the pent-up force of his prototype 256-line writing machine propelled Houser out of a fourth floor window.
In The Last Continent, the Bursar found himself at the creation of Fourecks. There, the Creator of the continent was tracing lines on rock in order to create the creatures that would populate the new land. This reminded the Bursar of Houser (except for the absence of screams).
It is not known if "Rubber" Houser is somehow related to Berenice Houser.