Essays?

The Stunt Pilot and Ali in Havana are different from most essays I've read, although they do accomplish the purpose of conveying information to an audience. Whereas they didn't lay out a clear thesis, they did give a multitude of details on their subject and get the author's viewpoint across. These essays are definitely somewhere between short stories and essays, and I don't know exactly what it is, but they have more of an essay feel, despite conveying information in a story-like format. Perhaps the many intricate details or the deep explanations are the cause of this feeling. The stories are so packed full of information, that they become essays. What makes it difficult to notice you're reading an essay is that every single fact is presented to the reader with an image, rather than simply stated and left alone. That attribute alone can give anything the tone of a story. An example comes in the explanation of gravity boots in The Stunt Pilot. Dillard explains the concept of gravity boots, and then gives the image of children running around to find their parents hanging upside down like bats.
I think an essay doesn't need a thesis, per se, but rather needs to educate a reader on a subject. Throwing in a point to prove is merely a bonus. Both of these compositions are loaded with information on a certain subject, and that's pretty much the only parallel I see with other essays.