Portable Observatories provides a guide to the immediate landscape, and a reference for later observations.
The NSF had issued a grant to the Exploratorium to create a set of interactive experiences around San Francisco's waterfront. The aim was provide users with guides to encourage focused and sustained observations of the natural and built surroundings. The exhibits were not to disturb the historical surroundings, and would ideally not create more structures along the piers.
The waterfront already had sets of kiosks for free magazines. I hijacked one and installed a sticker-machine mechanism that would spit out a printed cardboard sleeve for 25c. We had the mechanism set to dispense for free.
A photographer had already done studies on the changing plumage of developing gulls. I used his images for a card as an "observing guide". Fort Mason is one of the few places in the Bay Area where young gulls can be seen, as the birds roost on Alcatraz island.