ConversationChinampas: Narrator: Listen to part of a conversation between a student and the professor of his history of technology class. Student: Would it be okay to focus on something related to agriculture? Professor: Sure, farming technology is fine, as long as it's pre-modern. But this isn't a long paper, so you are gonna need to pick a specific area of pre-modern agriculture, like irrigation or food crops of ancient Greece. Student: I am actually interested in hydroponics. Professor: Hydroponics. Growing plants in water instead of soil. Student: Well, not in pure water, in water that has the proper mix of nutrients. Professor: OK. But is it a pre-modern technology? I mean, hydroponics isn't really my specialty but from the research I have read, we are talking the nineteenth century, maybe the seventeenth century if you really stretch it. Student: Oh? But the Aztec civilization back in the thirteenth century in basically where Mexico city is today ... An article I read said the Aztecs were using hydroponics in something they called ... I have got the word right here. Um. Chinampas. Professor: Chinampas, the so-called floating gardens. Student: Exactly. So yeah the chinampas, the article said very clearly these floating gardens are proof that the Aztec invented hydroponic farming. Professor: Well, chinampas are artificial islands built up in shallow lakes. Islands made from packed earth and weeds and uh, material from the bottom of the lake. They may have appeared to be floating in the water, but in fact they reach all the way to the bottom of the lake. So the primary growing medium, what the plants draw nutrients from, is actually soil, not water. Student: So the article was wrong about that? Too bad, it seems like a great topic, but I guess ... Professor: Wait a minute. Just because chinampas were not technically hydroponic doesn't mean this couldn't be an appropriate topic for your paper. Chinampas were still a great pre-modern technological achievement. I mean, they enabled the Aztecs to grow plenty of food in an area without much available farmland. Student: But I wondered why the author wrote that chinampas were hydroponic. Professor: Well it's pretty common for writers to generalize, say use a term like hydroponics to describe other types of agriculture. Personally, I would never say hydroponic except for plants growing in liquid. The crops on chinampas definitely benefited from the water surrounding them. But ... hydroponic ... Student: OK. So I will go with chinampas but leave out the hydroponics part. Professor: Actually, there's an important lesson here. We should pay attention to what happened in history but also how historical events are presented. Why, for example, would writers use a word like hydroponics so casually? Student: I guess 'cause it's a popular topic people wannna read about? Professor: Or to help modern-day readers to understand something historical, maybe these writers think a familiar frame of reference is needed. Student: Well that article was in a popular magazine, not a scholarly journal for historians. Professor: OK. But historians sometimes do the same thing. Student: So I guess then that all historians might not describe chinampas in quite the same way either. Professor: Good point. Why not look into that too? And include it along with your description and analysis.