From Frankfurt to Fortuna, Yerevan to Eureka, a red octagon means "stop." No matter the language, the symbol is universal. Yet compared to ubiquitous circles, squares and triangles, octagons are rare. Other than stop signs, you might find them in hot tubs, fancy dining tables ... and the Eureka Carnegie Free Public Library, now the Morris Graves Museum of Art.

The building is a fine example of brick classical revival, a testament to the quality of both the original construction and the extensive restoration of 10 years ago. The rotunda is octagonal, with eight two-story redwood pillars surrounding the original ceramic mosaic floor.

The City of Eureka pioneered public libraries. Our first dates to 1859, although they were always located in rented quarters until the Chamber of Commerce obtained a $20,000 grant from the Carnegie Foundation in 1901. The new library was built by Ambrose Foster (builder of Eagle House Inn) and opened three years later. It was in business for nearly 70 years, until 1972, when it merged with the Humboldt County Library.

Eureka's was one of 2,509 public libraries funded by Scottish-American businessman and philanthropist Andrew Carnegie, whose lasting legacy was based on his commitment to give to "the industrious and ambitious; not those who need everything done for them, but those who, being most anxious and able to help themselves, deserve and will be benefited by help from others." All of his libraries, including 1,700 in the United States, adopted what was at the time an innovation: Public access to the stacks to encourage browsing. Before then, you had to ask for a book by name, since the librarian was the only person allowed near the shelves.

Compared with most Carnegie libraries, Eureka's octagonal design is a rarity. In the original construction, the rotunda was graced with a tin and glass dome, but this was removed following earthquake damage in 1954. During the renovation of 1999-2000, a false ceiling was eliminated, opening it up to the airiness of an octagonal skylight that shows off the eight-sided room to the best effect.

Speaking of octagons ... a trick question when I was a high-schooler was "What's the area of a regular octagon having sides one foot long?" The quick and dirty (and wrong) answer is to think of an octagon as a 3 x 3 grid minus the corners, for an area of 7 square feet. The problem is that the initial assumption of nine squares is wrong, and you need Pythagoras to come to the rescue, as shown in the diagram.

Next time you're at Morris Graves, take a long moment to appreciate what is surely the finest octagon in Humboldt.

Photo 2 caption: The area of a regular octagon with one foot sides is the area of the bounding square (1 + 2b)² less the four triangular cut-outs (totalling 2b²). In triangle PQR, Pythagoras tells us that b² + b² = 12, i.e. b = about .7, giving an area of about 4.8 square feet.

Barry Evans (barryevans9@yahoo.com) is more an octagon than a square. He lives in Old Town Eureka.