You (all) recall my original query about a 1920 apartment house at 245 West 75th Street, with "one of the nicest details I've ever seen: at every fifth course, the masons laid the mortar with a continuous strip of copper right in the middle of the bed." First, I should have noted that it is every fifth bed >>for the first two floors only<< which further supports my surmise that it is decorative, not functional. Second, I took a hammer with me today, because I wondered if it might be lead, instead of oxidized copper. It's not. It's slate, very thin flats of slate. Christopher -- **Please remember to trim posts, as requested in the Terms of Service** To terminate puerile preservation prattling among pals and the uncoffee-ed, or to change your settings, go to: <http://listserv.icors.org/archives/bullamanka-pinheads.html>