Some queries were evergreens, so the librarians kept the answers handy on 3-by-5 cards:
What was Dorothy's last name in The Wizard of Oz? (Gale) Who said, "When I was a boy, the Sioux owned the world."? (Sitting Bull) What's the geographic center of Philadelphia? (Sixth and Erie)
Callers wanted to contact companies that had sold them lame products. Bill collectors asked for help with reverse directories so they could track down deadbeats.
Well, all that was so last century.
Today, there's one full-fledged Know-It-All left - Lori Morse, a librarian who runs the General Information department. She's backed up now by nine less-seasoned librarian assistants.
Where the department used to field 400 calls a day, now phone requests for what Morse calls "ready research" can be counted on one hand.
"We get maybe a couple a week," she said. "We've turned more into customer service representatives - people needing to renew books, needing help downloading e-books."
The bullpen where they worked, on the main library's second floor, has been dismantled, the book collection decimated. The three librarian assistants answering questions on the day of my recent visit were squeezed into a room off the second-floor hall. No questions came in that weren't essentially for tech support.
What's changed everything is the popular access to information. Morse recommended that I search for the percentage of Philadelphians with Internet access on the library website. Read the Pew report on the subject, she urged.
Instead, I tried the website's "Ask Here Pa." feature, which uses chat software to hook up the curious with the professionally resourceful 24/7.
"Librarian Phil" informed me that my local librarian was not at hand, but he could help from the United Kingdom. He took a minute to find a Technically Philly link that set the number at 45 percent.
Based on the activities of Morse's staff, you'd think the number was higher. She let me look over her shoulder as she paged through screen after screen of queries her staff had handled during the previous week via e-mail and chat.
It's here where you'll find the time-honored service of answering stumpers.
One correspondent wanted to know when Columbia Avenue became Cecil B. Moore Avenue? (Name change took effect in 1987.)
There is something about communicating by computer that brings out the jerk in people. One chatter wanted to gauge the popularity of the first name Strauda in Pennsylvania. The librarian responded that she'd found many between the mid-1800s and the early 1920s. Then the person on the chat descended into childish profanity.
The staff keeps boilerplate language for those occasions, and the librarian replied, "Due to your behavior, I must end this session."
Two inquisitive correspondents - or maybe a single persistent one - wanted to know why passing gas can be smelly, although the language used was more blunt.
One version prompted a boilerplate brush-off, while the second scored: "The metabolism of sulfur-containing protein and amino acids in the intestines."
A handful of questions came from places like Japan and Italy, where bargain hunters wanted to buy a $35 annual library card for the almost 12,000 e-books that can downloaded. It's a whole new world.
To keep up, Morse has had to become a gadget guru. "I just bought my young niece a Kindle. When iPad2 came out, I got one. I'm on my second e-reader. I can't help people unless I know these things myself."
Contact Daniel Rubin at 215-854-5917, firstname.lastname@example.org, or follow on Twitter @danielrubin.