so you want to see smoke??? I was thinking just intensify it wilth local bleaching in the darkroom...you can fix all them old photos too--and let's face it---you ain't gonna be lighting smokebombs or using fog machines somewhere public

the bleaching would actually be pretty easy to do without too much experience--jst dont color outsde the lines....use tape or a ruler to guide the bleach in straight line outlines from the window...you can make like a "bleach pen" out of an old fountain pen to draw a bunch of narrow bleach beams in there...just make sure you miss a few beams and you get that "shadow in the beam" effect

I'd stay away from anything but something benign for "smoke".....maybe use ddry ice? or boiling water on a towell if you absolutely need the smoke in the room--that would sure work if it was cold...even them fine mist aerosol humidifiers can work if you can get it close enough....just dont' wanna damage the surroundings is the thing...and anything that smokes these days you're gonna be explaining why you brought the"bomb" into the library to the officers answering the call