A voyage in space; a course of six lectures "adapted to a juvenile auditory" delivered at the Royal Institution at Xmas 1913 (1915)
Turner, Herbert Hall, 1861-1930 · London Society for Promoting Christian Knowledge · leaf 39
f the foci. Once when the latec 18 A VOYAGE IN SPACE Sir Robert Ball (who several times gave theseChristmas lectures) had mentioned this fact thatthe Sun occupies one of the foci of the ellipse, hewas earnestly implored by a lady after the lectureto tell her which of the foci was the one. I am… … DRAWING AN ELLIPSE (FIG I.) one (which of course was right in any case), andthe lady thanked him warmly and went away quitesatisfied. But whichever focus we choose it will benearer one end of the ellipse than the other. NowKeplers second law tells us that the planet movesquicker when it is near the…
Astronomy -- Juvenile literature
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