This is a presentation that I gave at the Tenderloin Museum in San Francisco in 2017, the 50th anniversary (approx.) of The Invisible Circus at Glide Church. Click on the image below to be taken to the page on the Digger web that displays the slides and corresponding notes.
digger feed: dinosaurs are dancing 
Eric, I wish I had seen your presentation. I attended the CIRCUS on so many levels. Your work is stunning.