Looking Forward to Monday Morning
A series of essays on business, architecture, and the business of architecture.
Why are Manhole Covers Round
by Daniel Frisch
Posted May 12th, 2019

Come visit us on Fifty-Sixth Street and you will find hanging behind my desk a full size color rubbing of a NYC sewer manhole cover. Produced by an artist-friend in the early nineties, the piece of art is one of my favorites. Not only do I admire the image, and the story of its creation, it has also become a mute accomplice when interviewing potential employees. Many have heard the urban legends surrounding Microsoft and Google interviews featuring math riddles designed to decide which of the Mensa candidates should be hired.

For me, I borrowed an interview question from a cousin who runs a large private company here in Manhattan: “why are manhole covers round?” Most young people coming to interview at DFA have not heard the question and become off-balance when asked – maybe not as much as “tell us about your five-year plan” – even if they should be. Imagine being twenty-something, sitting in an office with a middle-aged architect and a couple of associates at a firm where you would like to get a job offer, and being asked why manhole covers are round. On the surface, the question is simple and seems like something a prospect with a degree from a top-tier architecture school might be expected to know, and yet, most don’t.

Assuming a candidate does not know the answer, the candidate has to make a series of quick decisions, influenced by trying to figure out the context of the question. Why have I been asked this question, and not about my portfolio, academic accomplishments or career goals? Very often, the first response is to ask if I could repeat the question. Next comes the guessing game. The two most frequent guesses are that round covers can be rolled from place a to b, and that a round manhole cover would save material over a square. Both of these are true, but are not the real reason. Only once in a great while can a candidate figure out on the spot, even with prompting, that the reason is to save lives; manhole covers cannot fall through the hole no matter which way they are oriented.

Provided the candidate does not come to the interview knowing the answer, nor is one of the few that quickly stumbles upon the answer, our conversation becomes very informative. Going through the first couple of guesses goes quickly, and we can talk about how one solves a problem when the answer is “I don’t know.” Most candidates are very uncomfortable admitting a lack of knowledge, as I am certain I would be if the roles were reversed. What we like to see in a candidate who engages in a conversation filled with questions and follow-up questions. A robust back and forth is better than fielding ever further afield guesses, or responding to a request to Google it.

DF, 5-12-2019