Template for drawing the outline of Jupiter

Card disc with dark blue wash/cream and blue ink lines across made by John Willis, undated. It's inscribed "... Jupiter ... the Earth" [relative proportions] This is a template disc for drawing the outline of Jupiter. It's not round but flattened; the circle is ellipse. One of 275 pencil, ink and colour wash observations of the Sun and Jupiter made by Willis in Folkestone between 1879 and 1906.