Welcome to the forum.

That is a remarkable find. Your .22 Hand Ejector was also known as the Ladysmith as DWalt posted above. It's built on the M size frame, and is the smallest hand ejector model made by S&W and only in .22 cal. Produced from 1906 to 1921, in three different versions that all look very similar, with several barrel lengths.
Please share with us how you came to find this very desirable collectible model in the basement of your old house! It's value is roughly between $1500 to $2000.

Was it secreted away in a hiding place? Did you inherit the house from family members that may have owned it? How long did you live in the house before you discovered it?

Thanks for sharing it with us. Do you own other guns or other Smith and Wessons?

__________________
Jim
S&WCA #819