Originally Posted by
elnan
I started to comment on this post last night, but canceled because I felt someone more experienced than I would respond soon. But..., how can I look at ISMACS and come up with a different answer than what I now see posted? I read it as G4818430, a class 15, 50,000 allocated June 1910. Now, after reading the other posts, the number is farther down the list as a Class 115, 10,000 allocated July 25, 1916. Is there a secret to reading that list of serial numbers?
Count the number of digits in the serial number. Singer made millions of machines, so there's a six-digit G481XXX in 1910; six years later, the G series was up to a seven-digit number, G481XXXX. It's an easy mistake to make.