PRIMITIVE ASTRONOMY. 433 
one day as another, and showing no perceptible change in their 
movements. 
ISTor was his perplexity diminished when he found that what 
applied to the Sun was still more strikingly manifested in the 
movements of the Moon, for not alone did her course in the 
heavens vary from day to day, but with it her very appearance 
became changed. 
Sometimes he found her highest daily altitude to be less than 
that of the Sun in the depth of winter, whilst at others it was even 
greater than that of the same luminary at midsummer. Again, 
at one time, the Moon appeared to be advancing towards the 
Sun in the heavens, and at another to be receding from the 
position which he occupied; whilst, strange to say, the nearer 
she approached him the less luminous she became, assuming at 
length the form of a thin bright crescent, whilst, with increased 
distance, came greater brilliancy ; and, as she receded from the 
Sun, the crescent gradually expanded into a broad circular 
luminous disc, which almost sufficed to convert night into 
day. 
But another and a still more surprising phenomenon was soon 
revealed to the wondering gaze of the early student of the 
heavens. Even the stars themselves did not appear in every 
case to be fixed in the celestial vault, and one bright wan- 
derer* after another seemed to start from his fixed home in the 
heavens and slowly to mimic the movements of the great lumi- 
naries of day and night, until no less than five had been dis- 
covered who refused to be held by the inflexible bond that 
fettered all the rest. 
Judging from their degrees of brilliancy and the comparative 
changes of position to which they are subject, modern astrono- 
mers are disposed to believe that first Venus, next Jupiter, 
then, consecutively, Mars, Saturn, and Mercury attracted the 
attention of the star-gazers of ancient days ; and it was soon 
discovered that two of these planets — Mercury and Venus — 
were nearer to the Sun than is our Earth, and that they actually 
passed behind it and revolved round that luminary. t 
How great must have been the perplexity of our ancestors as, 
one by one, these abnormal and apparently contradictory phe- 
nomena forced themselves upon their observation ! How 
troubled they must have been to account for these apparent 
changes in the regular order of nature as conceived by their 
predecessors and themselves ! 
The Sun, indeed, revolved round the Earth at regular inter- 
* Hence called “ Planets,” from a Greek word signifying to wander. 
t The ancient Egyptians were well aware of this fact. See “ Chambers’s 
Handbook of Astronomy,” diagram on p. 25. 
