With the information given: Sounds like a .38 Military & Police Model 1905 2nd change. Produced between 1906 and 1909. You won't find a model number in the yoke cut, that didn't happen until 1957. Your gun was 50 years old when that started. If your going to fire it do not use anything but standard velocity .38 S&W specials. NO +P's
If that number nine is not real then you could have a .38 Military & Police 1st Model also refered to as the Model 1899 Army-Navy Revolver. They were made from 1899 to 1902. That conflicts with the last patent date on your gun.
The serial number should appear on the bottom of the grip frame, the bottom of the barrel where it's flat, the back of the cylinder, perhaps on the yoke either where it can be seen when the cylinder is open or perhaps look through the charge holes and it will be on that part of the yoke and pehaps on the back side of the extractor star and finally look on the inside of the right stock panel where it will be either stamped, in pencil or greese pencil.
Yes a picture/s would be nice as well as anything else you can tell us about the ole girl.