1840s: Milk production in dairy farming is all done by hand.

1878: The first commercial milking machines are produced inAuburn, New York.

Today: Dairy farming is automated. Cows are kept in small enclosures that allow no room to move and seldom come into contact with humans.

1840s: The typewriter is a new invention. Patented in 1843, it uses the concept of the moving carriage to make letters strike evenly.

1878: The typewriter is greatly improved when the Remington Arms Company added a shift key that would allow the same document to include lower—and upper—case characters.

Today: Typewriters are practically obsolete. Word processing makes any desktop system capable of professional-quality graphics.

1840s: The first rail lines are just beginning to connect major urban areas, with passenger train travel starting in the 1830s. The only transportation available to inhabitants of Egdon Heath is primitive, such as horse-drawn...