It's in the Laurelhurst neighborhood, just a bit south of the National Archives - Pacific Alaska Region facility.

Just across from the back of University Village, around the corner from Benton's Jewelry Street Clock.

The ball in New York's Times Square is a "time ball". I've never seen one in person, but apparently they were used to convey time to ships, by dropping the ball right at 1pm. They still exist, and here's one in Greenwich, England on the Thames river, courtesy of tderego on Flickr:

So this was the inspiration when the New York Times electrician built the original Times Square Ball in 1907 at New York's premiere public plaza.

Well before that, Seattle's premiere public plaza - Pioneer Square - had its own time ball just a half block away. Click through to this University of Washintgon archives photo of 1st and Cherry. If you look across the street, you can see a pole right behind the closest horse-drawn wagon. It's in front of the light awnings, and it clearly has a metallic ball on top and maybe a small flag.

How did I find this oddity? I was scraping Google Books and found this in the classifieds section at the back of the September, 1903 issue of The Coast:

At the end of the copy is the odd sentence "The time ball stands in front." At first I thought it must be a street clock with a round top, like the one that still stands in front of Joseph Mayer's old factory.

Finding the clock should be easy enough at that point, just a matter of finding what the building at 713-715 First Avenue looked like to spot it in a photo. Of course, I was surprised to find no clock. And then the weird post jumped out at me.

I still don't know alot about Gerhard Benninghausen. The Coast ran a story about him in 1904, saying he opened his watch repair shop in Seattle 19 years earlier. Checking the city directories, he's shown as working for Kimball & Son in 1884. That puts him in the select group of pre-Fire jewelers.

I know that he was eventually bought out by an employee of "MacDougal-Southwick", which he mentions being next door in his ad. Louis W. Suter worked for MacDougal-Southwick in 1891, and then became a travelling jewelry salesman. He went north to Alaska in 1900 -- three years after the gold rush started -- and figured out how to get rich by doing business in jewelry in Nome, Alaska. In 1907 he bought Benninghausen's Seattle store, which already wasn't listed in the 1906 city directory. It earned Suter a bio in the March, 1907 issue of The Coast. Oddly, Benninghausen opened up a new store later on and is listed in the 1920 Polk guide.

The photo at the UW archives is undated, but Benninghausen didn't move there until 1900 at least (I need to check a few more Polk guides). Meanwhile, the street clock on the right in the foreground belonged to Albert Hansen. He replaced it in 1906 with a big 4-dial affair. So this photo is from 1900-1906, and I should be able to narrow it down a bit more.

Moreso than the date, though, the pressing question is, how on earth did this time ball work? Was it only dropped once a day? Was it automatic? Did it perhaps signal that the time for streetcar departures? I'd love to know how it worked and what it meant to people.

The Carroll family donated their clock to Seattle's Museum of History and Industry, who installed it at the entrance to the museum. The museum will be moving to the historic Armory Building at the south end of Lake Union in 2012, and the clock will move again with them.

Here's the history of the clock as told on the old Carroll's website:

"In the year 1913, Thomas J. Carroll commissioned Joseph Mayer and Sons to create the magnificent clock standing outside our store and which has become a historical landmark of Seattle's downtown community.

"Our clock has been featured in the publication Historic America - The National Trust for Historic Preservation 1995 Engagement Calendar, amongst many other publications.

"Carroll's clock features a key-wound gravity driven pendulum movement visible at street level through the beveled glass side panels. The movement was manufactured by Howard and Company. The weight of our clock is estimated at 2 tons and is twenty feet in height. Winding of the clock movement is a weekly occurrence and a Monday morning tradition."

I've had the immense pleasure of winding the clock once myself at its new home.

At its old home:

Northeast of the intersection of NW 84th and 15th NW is a broad, fenced off parking lot.  On the edge is this monolithic clock.

The clock's days are numbered. 

It was once part of Washington Federal Savings Bank's Crown Hill location.  The bank now lies shuttered, half of its lot fenced off.  The entire property belongs to neighboring Safeway supermarket.  Safeway has been in a battle with the neighborhood for several years to build a discount gas station on this lot, and seems to have finally won.  The gas station is going to be built on the bank site.  I don't think the clock will survive.

I don't have exact dates on the clock, but the bank building itself dates from 1971.