This is really very interesting.  What did the trainee aim at?  A target on the wall?  All this is before electricity, let alone any sort of electronics.  Simply setting up the machine must have been time consuming.  I assume that once set up, in a basement armory (gas lights), that the installation was more or less permanent.  Have any of these devices survived?  Any of the instruction manuals?  Or miniature targets?

All this makes me ask if there is a Krag museum anywhere?  tbergdall's rifle belongs in it, as does the carbine with New York letters burned into the stock.  I say Krag museum, because none of this would ever be shown in a museum dedicated to public schools.