By: William & Alexander Keith Johnston
Date: 1903 (published) Edinburgh
Dimensions: 9.75 x 12 inches (24.5 x 30.5 cm)
Plate VII of Thomas Heath's Popular Astronomy provides a full illustration of rotation and revolution of our known solar system (as of 1903). One Table offers time in days, hours, and minutes for each planet to complete a full rotation upon its axis. What's interesting is that while earth takes 23 hours and 56 minutes to complete the process, Jupiter completes a single rotation in just 9 hours and 55 minutes while Saturn takes 10 hours and 14 minutes. A second table offers periods of revolution around the sun and mean distance of all known planets. Surrounding the print in the border are various astrological constellations placed in their general location and direction from the sun.
This chromolithograph print was one of twenty-one plates published in Thomas Heath's 1903 edition of Popular Astronomy. The plates were produced by W & A.K. Johnston, Scottish brothers who set up their own printing business in Edinburgh after preliminary study under the Scottish globe maker James Kirkwood.
The prints produced for the Popular Astronomy offer a unique view of our understanding of the Universe at the turn of the 20th Century.
Condition: This print is in A- condition with vivid original color, on clean paper surrounded by full and even margins on all sides. Some light yellowing of the ink is apparent inside the lower table.