ADVERTISEMENTS.
SCIENTIFIC
BICYCLE MAKING
The ball bearings of a bicycle must be very hard. But they must not be brittle, or they will break easily. The Columbia method is right. Soft, tough steel is forged to the shape required, machined down to exact size, case hardened to diamond density on its surface, and then polished. Such bearings rarely break, while they give the matchless ease of running that makes
Standard of the World
$100 to all alike
Columbias in construction and quality are in a class by themselves.