Latitude exact relationship of parallels and meridians with horizontal and vertical: both are complicated curves. On the sphere the normal passes through the centre and the latitude () is therefore equal to the angle subtended at the centre by the meridian arc from the equator to the point concerned. If the meridian distance is denoted by then where denotes the mean radius of the Earth. is equal to . No higher accuracy is appropriate for since higher-precision results necessitate an ellipsoid model. With this value for the meridian length of 1 degree of latitude on the sphere is (60.0 nautical miles).
The Last Dog on Earth appeal to teen readers. "The Last Dog on Earth" was included in the "What Ails You?" category, comprising literature "about how diseases, disorders, and other general health related symptoms affect our lives". In a 2005 interview, Daniel Ehrenhaft mentioned that a school in Chicago created an extracurricular activity wherein "kids designed games and gadgets", having been inspired by Logan's hobby of inventing devices. "The Last Dog on Earth" has received mixed reception from critics, who have praised the plot, but criticized the heavy use of coincidences to advance the plot. "Kirkus Reviews" commented that "happenstance plays a large role in