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> Unfortunately, no one has as yet devised a satisfactory machine for automatically sweeping and scrubbing floors, and it is likely that these labors will be ge

> Unfortunately, no one has as yet devised a satisfactory machine for automatically sweeping and scrubbing floors, and it is likely that these labors will be generally performed by hand to the end of the chapter. But the toil has been lightened by improvements in the implements used for such purposes, and there will undoubtedly be further advances in that direction. The number of patented mop wringers, for instance, is very considerable, and rotary floor sweepers, like street sweepers, are already in use. Sure enough, the modern vacuum cleaner would arrive less than 30 years later, invented by department store janitor James Murray Spangler in 1907, who sold the patent to William Henry Hoover.

laser 7y ago
> It must be remembered, also, that labor-saving devices, and indeed inventions of all kinds, often absolutely lessen demand instead of increasing it. Suppose, for example, that the many attempts at producing a satisfactory traction engine should result in success; is it not evident that the number of horses in use would be greatly diminished? This would similarly reduce the demand for horseshoes, horseshoe nails, currycombs, and harness of all sorts, every one of which now forms the centre of extensive manufacturing interests, employing many men. Also prescient, John Froelich got such a tractor working 14 years later!