Although called a changing box this is a transfer box. It was quite popular and sold for many years. Most sizes up to 10" x 12" were advertised. A 10" x 8" box cost £5.5.0, brass binding was extra.

To load, a dark slide is slid into the brass fitting on top of the box, part way along the box is a stud which is pushed aside by the dark slide, this opens the shutter in the box. The face of the dark slide consists of a hinged panel, this is now released by a catch and springs back a short way which opens the shutter in the dark slide. The glass plate is now free to fall into the dark slide, the panel on the dark slide is then pressed down which closes the shutter making the dark slide light-tight. The top of the transfer box can be positioned by a tambour arrangement.

The changing box was shown at a London Photographic Society meeting in April 1875.