One of the most remarkable examples of Inca engineering was their elaborate network of roads, parts of which survive today. Log, stone, pontoon, and suspension bridges were built to span streams, rivers, and chasms, and shelters and storehouses were spaced a day's travel apart. These were maintained by nearby villages, which also supplied messengers for their sectors. Messages or parcels could thus be carried throughout the empire quite quickly, with runners able to cover what distance in a day?
Hans Christian Andersen
Back in the day
The distance from Earth to Mars fluctuates between approximately 35 million mi (56 million km) and 63 million mi (101 million km). In 1999, NASA's Mars Polar Lander, on a mission to analyze soil samples, made the long journey to the Red Planet only to fail to re-establish communications following its entry into Mars's atmosphere. After the lander was declared lost, an investigation determined that it likely crashed onto the Martian surface. How long did it take the lander to reach Mars?
Born on a day like today
Mott was an American social reformer and women's rights advocate. She attended a Quaker boarding school near Poughkeepsie, New York, where she later taught, and became an official Quaker minister in 1821. She was active in the antislavery campaign and lectured widely on social reform. In 1848, she and Elizabeth Cady Stanton organized the Seneca Falls Convention, which launched the US women's suffrage movement. On what issue was Mott's stance at odds with that of the mainstream women's movement?