An introduction to astronomy: designed as a text-book for the use of students in college. By Denison Olmsted ...

'220 TIM PLANElTrN S.
conljtlldction, backward when near the inferior, alnd is statiollary near the points of grcatest elongation. The planet movscsoimetimes very slowly, and then rapidly; at one tille back-ward over a simall space, and then forw ard for a great distance.
cFig. p69../
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2.
(f tle cai-t. t.Yet all these apparetn irregularities o- are owiog tlo the tlwo
causes already advertecd to, viz., the effects produlmiced by perspcctivc, and by the tm otions of the spectator himself.'enns
exhibits a variety of' motions similar to tllose of McMicrery, except tfhat the changes do not succeed each other so rapidly,,siilce her period of revolution approaches more nearly to that
of thie earth.
360o. l'he apparent motions of the stperiorw planmets are, liko