It might seem like one of those trivial things that’s just always there, much like campus lamp posts and perfectly manicured lawns. But have you ever stopped to think — how is the Old Main clock run?

Well, maybe not. But now that you’re thinking about it, I’m sure you’re a bit curious.

The original Old Main clock was donated by the Penn State class of 1904. Although the original Old Main building was erected in 1859, a fire in 1892 burned down part of the structure’s roof. The building itself remained upright, but the roof had to be remodeled. The renovation was completed by Bellefonte architect J. Robert Cole.

Cole crafted a roof for the building that featured a straight mansard design centered around a tall, square bell tower. About a decade later, the original 1904 clock was presented, and the Old Main clock as we know it was born.

Though the design of Old Main has since changed, the original clock was never removed. The clock we see today, with modernized mechanics of course, is still the same machine donated by the Class of 1904.

Today, the clock runs on the power of computerized sensors. The sensors pick up on the positions of the hands of the clock and adjust accordingly.

That’s why events like daylight saving time require no additional manual adjustment — the clock is pre-programmed to automatically correct for time changes. 

The computer sensors work the same way for power outages, too. If the power goes out on campus, once it comes back on, the clock’s hands rearrange themselves to mark the correct time.

With modern technology and computer sensors, the Old Main clock works as efficiently and effectively as one could hope. There isn’t much manual labor involved.

And there you have it. Now, the next time you’re walking past Old Main with friends, you can stop and amaze them with your new found knowledge of how the Old Main clock runs.