ScientificAmerican1921-03-05.jpg Scientific American 1921-02-26ThumbnailsScientific American 1921-03-12Scientific American 1921-02-26ThumbnailsScientific American 1921-03-12Scientific American 1921-02-26ThumbnailsScientific American 1921-03-12Scientific American 1921-02-26ThumbnailsScientific American 1921-03-12

Building a skeleton pattern for a water-turbine spiral casing. Also, "Who shall work the farms?" and "Making weather to order".