Watch: Professors' Dirty Looks
At least into the 1990's, the fifth floor of Griswold Hall was the Faculty Library, and people who weren't professors weren't welcome there.
One time, there was to be a presentation there on changes in health benefits for Harvard faculty. The professor I worked for wasn't going to be able to attend, and he asked me to do so in his stead, pay attention, and take notes. Some of the profs there apparently weren't entirely happy about my presence, until I asked a few questions that resulted in the presenter's clarifying some points.
The professor I worked for had the walls of his office in--what's now--Areeda Hall lined with hundreds of volumes of various bound reporters, on shelves that extended far higher than I could reach without a high step-stool or ladder. At the end of each summer, many volumes his research assistants had used during the summer in another room while helping prepare revisions to his parts of a multivolume treatise had to be re-shelved, older volumes taken away, and space made for forthcoming ones. It was very hot work. One time, I took off my outer shirt while doing it. Archibald Cox walked by and gave me a look that indicated that that was definitely not proper HLS attire.