A 1,500-foot tower at 18th and Arch?
  With no known financing, no office tenant, a weak credit market, and 20 years of stagnant Center City commercial property markets?
  "Ridiculous," says Glenn Blumenfeld, a partner at office-tenant representative Tactix Real Estate Advisors in Radnor.
  "A dream," says David J. Campoli, regional manager for office landlord HRPT Properties Trust.
  But someone drew up a nice sketch, and someone else told a pleasant story, and you can read it here.
  "Everybody would love to see it. And it's the last good block of space in that neighborhood. But, until you have a tenant, and with the capital markets so jittery, I think we have to let it cook for awhile," said  H. Hetherington Smith, branch manager for tenant rep Studley.