They might have wondered at the circular spools, the huge platter, on which the reels of film - six for a two-hour movie, measuring 10,800ft or 3.3km - were assembled into a seamless whole.
The technology is fundamentally unchanged since the first public film screening in a Paris cafe in 1895: sprockets on a roller catch the film by holes along its edges and pull it through the gate in front of the lamp. Yet this 200kg assembly of hardware is virtually a museum piece.
And it seems so sudden: I remember attending a preview screening of Ralph Fiennes' Coriolanus less than two years ago, at which the distributor proudly announced that the release would be entirely digital. Now the changeover is complete. We still go to the movies, but we don't watch films: we watch digital files.
"The whole industry has changed," says Bridgeway co-owner Kelly Rogers.
"There are hardly any 35mm prints coming into New Zealand now. What it brings from the public point of view is a vast technical improvement in the experience.
"The image is crystal clear, the sound is good.The purists may complain, but digital is far superior. As the film wears down after successive weeks of playing it can get scratched. That's all gone."
Not all cinemas have disposed of their projectors. At the Victoria in Devonport, where they have been showing movies for 101 years, they still have one for the occasional heritage screening, but operator Philipp Jaser admits that it is driven by respect for history, not commercial necessity.
Likewise, Richard Dalton, of the Lido in Epsom and the Capitol in Balmoral, has completed the switchover to so-called digital cinema projection (DCP), but keeps a projector "in case".
"It's never going to happen," he says, "but I'm just an old romantic, I suppose."
Michael Eldred, the theatrical sales manager for arthouse distributor Madman NZ, says that the DVD contributed to the end of 35mm because it made cinemas' back catalogue easy to access. In that context, so-called repertory cinema, which played older films in an ever-changing procession (the Valhalla in Sydney's Glebe and Charlie Gray's Pictures) can't survive.
But it was advances in technology that set film's obsolescence in motion. A single film print - which costs around $3000 to produce - fills three large tins weighing 22kg. That's an expensively heavy piece of freight, but a digital cinema package is an external hard drive that can be dropped off by a motorcycle courier.
And it won't be long before the physical artefact disappears altogether and the data is simply delivered online; this technology is already being used to beam performances by the New York Metropolitan Opera and London's National Theatre, live to cinemas in the UK, US and Europe.
"I don't know where the hole in the ground will be that is big enough to take all the projectors in the world," says Eldred.
"It seems such a shame because they are beautiful pieces of equipment that have overnight become relics."
Like most people who work in the movie business, Eldred is a romantic too. "I can't help feeling that we have lost something," he says. "In a cinema I always like to sit in the middle near the back and I miss the sound of the whirring projector."
Projectionists, highly skilled operators, now look like going the way of the cobbler.
They have turned into IT people, though they doubtless get a bit of Schadenfreude when they read of screenings cancelled when passwords, called digital keys, don't work; when mechanical projectors broke down, operators would have them running again within moments.
As to the Bridgeway's projector, it will probably be at the dump by the time you read this.
"It's a shame," says Rogers, "but you know what: it's worth nothing."
