san-sing,
Yes, after about 1895 if I read correctly they used the common Class 15 bobbins.
Go to ISMACS: {
http://www.ismacs.net/singer_sewing_...ist/index.html }
Click on the "Classes from 1 to 99" section and scroll down to the 15s. There is much information and some pictures as well.
Joe
Last edited by J Miller; 03-21-2013 at 12:20 PM.