Foxflower that is a Singer Model 15, allotted on July 2, 1906. Wow, I did not know that the model 15 ever had the Sphinx decal - at first glance I thought you had a Model 127 because of the decal! Yours is the first 15 I have seen with a Sphinx Decal on the machine.
Yes, the serial number tells you all about your machine from the Singer site.
Nancy