The Talking Machine Forum — For All Antique Phonographs & Recordings

This is a very rare Edison S-19 Sheraton grill that is not mentioned in the Frow book. Note the precise linear hole diameter reduction when going from right to left.....the large holes let the large notes out, the medium holes let the medium notes out and the small holes let the small notes out. This linear reduction in hole diameter from right to left is a breathtaking invention that utilized a differential equation that contains one or more terms (the multiple sized holes) and the derivatives of other variables (i.e. the small holes) with respect to the another variable (i.e. the medium holes).

When you think you have seen it all.

I did a term paper on that in college. Pretty simple stuff really.

post deleted- I guess it wasn't funny.