Four For Four

1. "Guzzlers" are artificial waterholes distributed throughout the American West.  They are important to the survival of a variety of wildlife.

2. People are not allowed to pump their own gasoline in New Jersey and Oregon.

3. "For decades, people have puzzled over Racetrack Playa, where hundreds of rocks weighing as much as 700 pounds roam across the surface of the dry lake bed, leaving meandering tracks hundreds of yards long."  Now the process has been captured on video.

4. "Americans built more than one hundred thousand kit houses, sold mostly by Sears, in the first half of last century. These were shipped out on boxcars, complete, with between ten thousand and thirty thousand pieces, braces to brads. Midcentury, Popular Mechanics sold several varieties of home designs—the Modern House, the Family House, the Plywood House. There's no telling how many of those were built. Totman's precut house was sold as a concept listing the materials at three prices: $1,800, $2,800, or $3,800."