Head west on N Northlake Way; after 0.4 mi the road bends right and becomes Stone Way N; then immediately turn left at the light onto N 34th St. Take the third right (after 0.2 mi) onto Troll Ave and go up the hill two short blocks to N 36th St. At this intersection you will find one of the most amusing sculptures in the world: the giant Fremont Troll, lurking under a freeway bridge (Aurora Ave N) while ravishing a Volkswagen “Bug”. Take a picture and resume west on N 36th St. After 0.6 mi the road bends to the right and changes name to Leary Way NW. After another 0.6 mi, turn right onto 8th Ave NW. Go 1.1 mi and turn left at NW 65th St. Go 1.4 mi and turn right at 30th Ave NW. After 0.1 mi, turn left onto NW 68th St; after one-half block park find the Nordic Heritage Museum parking lot on your left. Webster park is the very small park to its west, and the dial is easily found. If you are of Nordic Heritage or wish you were, by all means visit the Museum (information here http://www.nordicmuseum.org/ ), which celebrates the immigrant history of this portion of Seattle (Ballard).
View Seattle Sundial Trail in a larger map
This dial w
as built as part of the neighborhood-driven creation of Webster Park. Chuck Nafziger designed, fabricated, and installed the dial; he was inspired by a Chinese dial h
e saw in an exhibit. The shadow center of the gnomon/polar axis can be read to 1-2 minute accuracy, and the shadow of the disk (falling on the gnomon) allows the date to be read. Both the upper (summer half of the year) and lower (winter half) surfaces of the disk are finely marked with one-minute divisions; this type of dial cannot be used within about 3-5 days of the equinox because the sun is then travelling in the (equatorial) plane and no usable shadow is cast. The entire time scale is rotated by 9.6 minutes, in order to compensate for the shift from PST to the local longitude, although one still must adjust for the equation of time in order to compare with clock time.
A 20 cm (8 inch) diameter brass globe is mounted at the top of the gnomon; a world map is engraved on this globe, with Seattle on the top. The half of this globe that is lit at any time corresponds exactly to the half of the Earth that is lit at that same instant.
There is much explanatory material incorporated into the dial’s design. Other persons who contributed to the project were Virginia Lindahl, Lillian Riley, Peter Hirtle and Woody Sullivan.
Motto: “We did not inherit this land from our parents, we are borrowing it from our children”
http://www.wsanford.com/~wsanford/exo/sundials/wa/seattle/ - many photos of the dial, with tutorial links about equatorial and other types of dials