READERS RESPONDED with great passion to our January issue. Although Bill Gates's vision of the developing robotics industry instigated much debate, the majority of letters centered on Matthew L. Wald's article and its pessimistic view of corn-based ethanol fuel. Correspondents argued from all sides of this issue, although a large number echoed Joyce Ferree of Salida, Colo.: "Ethanol may not be the perfect fuel, but it is showing Americans that there are alternatives to foreign oil that stimulate rural economies across the U.S., improve our foreign trade balance and don't require our military to keep the supply coming.... Corn ethanol is not a 'bridge to nowhere' if we look at it as a solid foundation for a new industry to build on."

In "Is Ethanol for the Long Haul?" Matthew L. Wald speculates that ethanol producers may turn to coal or even electricity for process heat instead of natural gas because that fuel has become expensive. Although a small minority of new ethanol plants use coal instead of natural gas, an encouraging trend appears to be a switch to renewable biomass for processing, which greatly reduces fossil-fuel use. Several new and existing ethanol plants have taken this path, yet Wald makes no mention of it.