It is a .38 Safety Hammerless, probably from 1900-'02. Others here track SNs of specific models closely and may get you a specific year. Hope this is helpful.
Alan has the date as close as possible, since there is some random order to shipping this model in the early 1900s. It would be a 38 Safety, 4th Model and classified an a modern firearm by the BATF. Antiques are found with serial numbers below 119,900.