The online Beagle library now allows anyone to see the amazing range of visual imagery that Darwin poured over during the voyage. See the illustrations here Humboldt's illustration of his famous ascent of Mount Chimborazo in the Andes in 1802.
And it may be our busy lifestyle that keeps us from napping. While naps do not necessarily make up for inadequate or poor quality nighttime sleep, a short nap of 20-30 minutes can help to improve mood, alertness and performance.
From 9-15 or 18 months, on average, your baby will nap two times a day. Although many people believe most babies transition to one nap at 12 months, the average age is actually 15 to 18 months.