It's that time of year again, when the thermometer drops below 40, and suddenly the streets fill not just with dry leaves and black ice but urban guys suddenly transformed into lumberjacks. The beards grow, the sweaters come out, and seemingly overnight, the cities are crammed with scrawny Hemingways. You know what I'm talking about: the Metrognome.The metrognome comes in several forms. There is the archetypal Pacific Northwestern/Western metrognome, of course, attired in flannels and beard year-round. The metrognome was originally identified, in fact, in San Francisco. The southern metrognome has been known to evoke the Civil War. Then there is the seasonal metrognome, who comes out only when the weather grows cold. This varietal wears a beard, yes, but his clothing also becomes considerably more rugged than is his wont, or than is necessary in an urban environment. The metrognome is not to be confused with the Bear, who is characterized by a certain natural burly hirsuteness. The metrognome transformation, by contrast, is completely inorganic and owes nothing to actual appearance. As "metro" implies, there is an element of deliberate grooming and styling involved. The metrognome will often claim a beard is for warmth. But there is also an element of dandified defiance to it: the metrognome says: I am not part of "the system." The establishment has no hold on the metrognome! His appearance implies: in my heart, I am cut out for the challenges of the wild. I master the elements and am obscurely connected to an earlier time. When the writers' strike occurred, talk show hosts couldn't go metrognome fast enough. Whereas most metrognomes have to deal with the awkward growing-out stage for a few weeks in November, their public shearing was a Samson-like loss of metrognome powers. And does the metrognome have powers? Well, anecdotal reports are inconclusive: some women find the metrognome cozy and cuddly; others somewhat silly and scratchy. One thing is for sure: he's coming to a microbrewery near you, and the time is nigh.