Taylor Hobson f1.5 5 inch Lens- Info Wanted

[Brian Dixon]

Hi, I am a complete and total novice when it comes to large format lenses. I think I have one... and would appreciate any information about this lens. It is a very large fast lens and is marked TAYLOR-HOBSON ANASTIGMAT LENS 5 inch f 1.5, the lens is about 4.5 inches long and the front lens is about 90mm across. It is a very impressive lens but I have no idea what it was used for, especially since it doesn't have a way to change the aperture (or focus). It looks very well made. Any information would be much appreciated. Thank you!

[Dan Fromm]

Two possibilities. Projection lens, lens for radiophotography (taking pictures of, e.g., fluoroscope screens)