Genetic analyses indicate that there were three distinct waves of prehistoric migrants from Asia to North America. Y-DNA haplogroups are indicated by the blue lines, while mitochondrial DNA is indicated by the yellow lines. (Note: Since this map was published in 2008, the M3 mutation has been grouped under the larger haplogroup Q. (So, Q-M3.)) Map by National Geographic Society
Relief map of a section of the Western Front, used by British generals to coordinate offensives. Allied trenches are marked by blue lines, German trenches by red lines. See it in 'Maps in the 20th Century: Drawing the Line' at the British Library until 1 March 2017. Read a review of the exhibition by the https://exhibitionologist.wordpress.com/2016/11/10/review-maps-and-the-20th-century-drawing-the-line/
The Geochron allows any observer to determine what time it is anywhere in the world. The colorful map is an endless belt that is driven slowly from left to right by an electric clock motor in synch with the rotation of the earth. Time zone boundaries are delineated on the map by dark blue lines which converge on lettered pointers on the top edge of the map. These letters identify the standard time zones and also represent the short wave radio prefix for that zone.