Today, we democratize ice cream. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Visiting my great-aunt at her old farmhouse was a childhood delight -- drinking in 19th-century smells and textures. Best of all was the taste of her homemade ice cream, rich with eggs and cream. Back in the city, at the corner grocery, I could buy three large scoops of the factory-made stuff for a nickel. It wasn't Aunt Mary's artery-clogging ambrosia, but it was still wonderful. Ice cream was among my primary pleasures in the 1930s.

The odd thing about ice cream is that it was around long before commercial refrigeration systems became commonplace in the 1870s. Ice cream didn't have to wait for that. Wealthy Romans packed snow in straw and brought it down from the mountains. They flavored it with fruit and served it at banquets. But it had the texture of ice crystals and it lacked the body of a dairy product. Roman ices were a far cry from ice cream.

Marco Polo found a recipe for a milk-based ice in 13th-century China. From then through the 18th century, closely-guarded ice cream recipes traveled the royal houses of Europe. King Charles I of England mandated that they not be served at anyone's table but his. This was no food for commoners.

Washington, Jefferson, and Madison all served ice creams at affairs of state. Like government itself, ice cream was about to be democratized, but it was still a terribly labor-intensive product. You have to hold a gluey mixture at sub-freezing temperatures while you steadily stir it to keep ice crystals from forming. Good ice cream is a texture as much as it is a taste. Making it is a process -- not just a recipe.

Nevertheless, ice cream became an expensive public delicacy in our new country. During the early 19th century you could buy it in New Orleans shops -- even in Kentucky. Nancy Johnson of Philadelphia made the big breakthrough in 1843. She patented the home ice cream freezer. Then she sold the patent for $200. By 1873 some seventy copycat patents had been filed.

After that, ice cream became an American staple. Jacob Fussell, an abolitionist Lincoln supporter, set up the first ice cream factory in 1856. The ice cream soda and the ice cream sundae followed. The ice cream cone was patented in 1903. It took off in America after it proved to be the most popular treat at the 1904 World's Fair in St. Louis.

What I saw at my great aunt's house was the passing on of the old nectar of Caesars and kings. What I enjoyed at the corner store was ice cream finally gone fully public. America had, at last, given all of us a joy once allowed only to royalty and their courts.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

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Funderburg, A., The Inside Scoop. American Heritage of Invention and Technology, Vol. 11, No. 3, Winter 1996, pp. 44-49.

Singer, C., Holmyard, E.J., Hall, A.R., and Williams, T.I., A History of Technology, Vol. 5. New York: Oxford University Press,1958. See entries indexed under foods/refrigeration.

A Thomas Mills and Brothers Ice-Cream Maker, 1870, at the Smithsonian Institution
Photo by Judy Myers, with permission