Columbia BM

 

 

The Columbia BM, also known as the "Home Premier" used the Higham loud playing reproducer found on the much larger model BC. This machine used the mahogany cabinet and motor of the model BG, much better suited for the home environment. The cost for this was $75.00

Daniel Higham applied for the patent for the BM reproducer mechanism in April 1906 and was granted patent #876,350 on Jan 14, 1908

 

This particular BM has a very unusual 2/4 minute change mechanism, unlike any other used on a Columbia machine. The ID plate had to be removed and a new intermediary gear is installed, also a new carriage drive gear. To switch speeds the drive gear is pushed to the right for 2 minute and pulled to the left for 4 minute use.

 

Close up of the shoe and wheel, the assembly that makes the amplification possible. The original wheel was made from amber and the shoe from gutta percha (a type of hard rubber) together the coefficient of friction is 1. The parts on this machine are modern plastic materials with a very low coefficient of friction between them. With this arrangement the machine does work but the volume is only comparable to a conventional Columbia reproducer.

Phonographs  Home