I admit to a fascination with Scientific American. I used to have a couple of decades of the magazine which I kept mostly for the Mathematical Games and Amateur Scientist column. Project Gutenberg has begun to digitize some of the 19th century copies, which are mostly of historical interest, but still can be interesting. For instance, the following issue:

Scientific American Supplement, No. 647, May 26, 1888 by Various – Project Gutenberg.

contains an interesting article by James Wimshurst on static electricity generating machines.

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