[78-L] Acoustic disc playback speed?

[L78rpm at aol.com]

In a message dated 1/25/11 3:45:09 P.M. Eastern Standard Time,  
audiotechtransfer at bresnan.net writes:

Victor  (early acoustics to 1909)          71.29  RPM
Victor (later acoustics 1909-1925)      76.59  RPM
Columbia (acoustic)               80.00 RPM
71 rpms --- perhaps a bit more or sometimes less, works well for Berliner  
discs of the 1890s.
 
Earlier Victors play --- in general --- from 74-76 rpms.
 
For later acoustic Victors I set the speed at 76.4.
 
My ear tells me that 80 rpms is too fast for acoustic Columbias, despite  
their suggested use of this speed.
 
Paul Charosh