It is a Polaroid 2100 35mm point-and-shoot. It was chosen because it has a motordrive and is cheap! Despite the name, it is a conventional 35mm film camera - not an "instant-print" type.

The intervalometer was cobbled together from a hobby gearbox kit. (More detail below)

As is common with KAP mounts, the camera is mounted upside-down for convenience. The photo at left shows the camera right-way-up... hence the mount is upside-down.

At right is a view of the gearbox and arm which make up the intervalometer.

With one single AA cell, the 4096:1 ratio of the gearbox provides around 40 seconds between shots - which means that a 24 exposure roll of film should last about 16 minutes (provided that the cell doesn't go flat!)