Among the many unknown treasures of the College are the three vertical sundials mounted on the exterior walls of Hubbard Hall. But these sundials, of a rarified breed called “fall decliners,” are not overlooked by all, they were the highlight of the annual North American Sundial Society (NASS) conference held in Portland this past June. 

According to NASS President and Co-Founder Fred Sawyer, fall decliners are sundials where the dial sits vertically on a wall that is not oriented directly east or west, requiring its lines to be asymmetrically distributed. The calculations behind a fall-decliner, Sawyer explained, are especially complicated and rich in mathematical theory, piquing the interest of NASS members across the country during their Maine sundial tour this summer.

NASS is comprised of sundial manufacturers, designers, craftsmen and theorists who flock to sundial hotspots annually to pay tribute to and discuss prominent dials such as the ones at Bowdoin.

The Hubbard dials first appeared on the public sundial registry, which is run through the NASS website. When the society looked for a city in which to hold the NASS annual conference, the Hubbard dials stood out as a compelling destination for the conference tour. 

“We looked up on the registry what we had, and the Hubbard Hall dials were clearly the best dials in the area. Portland doesn’t have much, but those are particularly nice dials,” said Sawyer.

According to Sawyer, the Hubbard dials are three of 800 registered sundials in North America (a modest number compared to the 15,000 in England and France). Though the Hubbard dials are a NASS landmark, Sawyer points out that the east dial is easily overlooked because it only indicates time from sunrise to noon. 

Sawyer also notes that while the dials appear to tell time incorrectly to us, they in fact display solar time. He attributes the appearance of error to the fact that 24 is only the average number of hours in a day, and from day to day our own clocks may be as many as 30 seconds off of standard time. At certain points in the year, the Hubbard dials appear to be as many as 16 minutes fast or slow, but they are, in fact, aligned with standard time.

For such dials requiring such meticulous mathematics, Sawyer praised the Hubbard dials as “particularly nicely done.” 

“[The Hubbard dials] were the highlight of the tour,” he said.