I NOTICED at the time of its publication in the Engineer Prof. Smith's communication of the discovery of an empirical formula which would represent the values of the total heat even more ...

Beneath the streets of hundreds of North America's oldest cities lies a network of pipes delivering steam heat to office buildings and hospitals. These steam loops could be a clean energy solution.

It's counterintuitive, isn't it? You'd think that moisture would make the crust soggy, not crisp. Nevertheless, it does work.

CHANG: Suddenly you have a superpowered steam heater, which is one reason they earned a bad reputation, says Dan Holohan. He knows that some city dwellers still open their windows during the winter.

Steam is sent to radiators, while hot water flows to radiators or radiant heating systems. Boilers are fueled by natural gas, heating oil, propane, electricity or a biodiesel-oil blend.