Between 1950 and 1967, CBS television ran a popular game show in which four panelists asked question in order to guess the occupation of a guest. The name of the game was “What’s My Line?”. Now you get to play the game except that you have to use observational skills rather than ask questions. What do you think is the occupation of the four men seen in this cabinet card photograph. Three of the men are in uniform and wearing hats displaying identification numbers. At least one of the three is wearing striped pants. The fourth man is well dressed and wearing civilian clothing and a light colored hat. He is also chomping on a cigar. My guess is that the men work for a railroad. It is also possible that they are firemen. Any comments conjecturing about their line of work, would be appreciated. The name of the photographer and the location of his/her studio is unknown.
THE CABINET CARD GALLERY 
Another (related) possibility is that they are conductors (Trolley? … horseless or otherwise). The hats look familiar and the number ID’s the person. The ‘Dispatcher’s body language exudes authority. His fingers look unfamiliar with dirty hand work (so-so for the other gentlemen). Note the jacket pocket … barely visible but kerchief in one … handy for transfers, etc. The coat often hung open for access to a coin changer (worn around the waist over a vest). I am probably wrong … sure would be nice to know the location. Thanks … I was a fan of ‘What’s My Line?’
I would agree with Bill Patterson. The number might also have been car number –