If you like 'em weird, this surely is one for you. The No. 4 Screen Focus Kodak combines the use of roll film with a ground glass. Not like many Folding Pocket Kodaks whose roll film back could be transformed into or exchanged with a plate back, but with a remarkable construction that allowed the roll film back to be swung out of the way to make place for the ground glass. In the video above you see the camera in this position.

Why did someone invent such a machine?
Anwser: to make roll film cameras an acceptable alternative for the serious amateur. The usual roll film camera of the 1900's had to be aimed with the help of a tiny reflecting finder. You did get some idea of what the camera was pointed at, but no more than that. Framing the image was guess work and focusing had to be done with a scale and pointer. For the family photographer this was just good enough, but the serious amateur who began considering the use of roll film asked for something far better. He wanted to focus and frame the image precisely, just like in the familiar plate camera.

In the usual roll film camera the film sits in the back and this back can not be taken off or opened without spoiling (part of) the film. So there is no way to put a ground glass in the back. Around the turn of the century (1900) several companies invented methods how it could be done and produced cameras like the Combination Hawk-Eye (1904-1905), Focusing Weno Hawk-Eye (1902-1903), Freewheel (about 1903) and No. 7 Focusing Buckeye (about 1904). There were others as well and you can read more about it in my (Dutch!) article "Focus hocus pocus" that was published in the Fotohistorisch tijdschrift of 2003, number 1. (See the menu.)
Some interesting details: the back that is swung up in the video is a miracle of storage. The dark slide can be stored in a slit in the back, but also the ground glass can be stored there. It fits in the slit in the short side. As if this in not enough, the No. 4 Screen Focus Kodak (made from 1904 to 1910) can be transformed into a real plate camera. How this is done, you can see in the other video.

Manual in rather worn condition, but very rare.

To make the No. 4 Screen Focus Kodak (1904-1910) a good alternative for the serious amateur, it combined the use of roll film and a ground glass. This I explain on the left.
To make the camera even more acceptable for the serious photographist, it could be transformed into a real plate camera. The complete roll film back could be taken off and a special glass plate back put in its place. This back has a built in ground glass, as you can see in the video. The camera is not really rare, 4000 were made, but the ground glass back is not seen often.
 

Ad in The Photo-beacon, 1905