This revolver looks like it is a Smith & Wesson DA from the early 20th century, right down to the S&W grips. However, it is actually a Spanish Eibar-made copy, and you can tell when you take a close look at the patent markings atop the barrel. Instead of "Smith & Wesson, Springfield, Mass, USA", it says:

Smill & Welson, Sprangfeld, Mus, EUA

Close, guys...but not quite!