Charles S. Lewis Baker (August 3, 1859 – May 5, 1926) was an American inventor who patented the friction heater.

Baker worked over the span of decades on his product, attempting several different forms of friction, including rubbing two bricks together mechanically, as well as using various types of metals.

After twenty-three years, the invention was perfected in the form of two metal cylinders, one inside of the other, with a spinning core in the center made of wood, that produced the friction.

The Friction Heat & Boiler Company was established in 1904, in St. Joseph, with Baker on the board of directors.

The most difficult part of the inventor's assertions to prove is that his system will light or heat a house at about half the cost of methods now in use.