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.
Napping Tips. Research has found that napping regularly may reduce stress and even decrease your risk of heart disease. To get the most out of a power snooze, follow these quick tips from Mednick: Be consistent. Keep a regular nap schedule. Prime napping time falls in the middle of the day, between 1 p.m. and 3 p.m. Make it quick. Set your cell phone alarm for 30 minutes or less if you don't want to wake up groggy. Go dark. Nap in a dark room or wear an eye mask. Blocking out light helps you fall asleep faster. Stay warm.