The barrel tips down and the hammer is exposed
Okay, that and the serial number narrows it down to two possibles:
A .32 Double Action 4th Model.
SN's ran from 43406 in 1883 to 282999 in 1909.
A .38 Double Action 3rd Model.
SN's ran from 119001 in 1884 to 322700 in 1895.
You'll need to find out the caliber (32 or 38) to know which model it is.