Scientific American, the oldest continuously published magazine in America, began life on August 28, 1845 as a 4-page, black and white newsletter. There were only a couple of illustrations. The cover model was one of the vastly improved railroad cars of the age, which could seat 60-80 passengers, "run with a steadiness hardly equalled by a steamboat," and (perhaps best of all) was capable of "flying at the rate of 30 to 40 miles per hour."
In this early incarnation, Scientific American was published weekly—"Every Thursday Morning" in New York and Philadelphia, promised a sidebar. Articles were packed together in that great "NO WHITESPACE!" style common to 19th-century newspapers. Besides that brief on modern train cars, the front page featured curated clippings from other newspapers and publications, ranging from an explanation of where the sound of thunder comes from, to a report from the "village of Moulton" about a levitating haystack.
There was poetry. There was a column all about new inventions—which includes, if I'm reading correctly, an announcement about the invention of the centrifuge. There was a long list of recently issued patents. There were descriptions of basic scientific principles and some gadget-hound fawning over Morse's telegraph.
If that makes good ol' Sci Am sound frightfully blog-like … well, yes. That's sort of an interesting point, isn't it? Meet the New Media, same as the Old Media.
During the month of November, you can acquaint yourself better with media and scientific history by browsing through online archives of Scientific American issues from 1849 to 1909. They're free to access, for this month only.