422 SIR JAMES SOUTH ON THE EXTENSIVE ATMOSPHERE OF MARS. 
acquainted with the bearing of the question, and ignorant of the colour as- 
signed to it by me, he replied, 4 Certainly a light red.’ Mars was now brought 
into the field with the star, and being asked what colour he now considered 
the star to have, he answered, 4 Certainly red, but not so deep a red as Mars.’ 
Looking at it again, he said, 4 Mars is the darker, but there is not a great 
deal of difference.’ ” 
44 1 now applied several other eye-pieces, magnifying from 7 0 to 548 times, 
and with all of them I felt convinced that the star was red, but not so deep a 
red as Mars.” 
44 Whilst the colour of 37 Tauri was fresh in my recollection,” I placed the 
Equatorial upon 42 Leonis, when it had nearly the same altitude as that star; 
I instantly pronounced the star 42 Leonis to be blue — light blue. The 
attendant was now requested to look again at 37 Tauri, and to retain its 
colour in his mind as much as possible : 42 Leonis was next brought into the 
field; he said, 44 This star is certainly not red at all; I do not know what colour 
it is, unless a light blue.” Alternating the examination of the one star with 
that of the other several times, and with various powers, he at last said, 44 It 
is certainly blue, and the first is certainly red.” 
The comparisons were repeated with the 12-feet Achromatic of 7f inches 
aperture, and the inferences drawn from them were the same ; and, if just, the 
observations of 37 Tauri and 42 Leonis are perfectly reconcileable. Hypothesis, 
therefore, is not needed, to explain under similar circumstances with regard 
to Mars, the 44 red” colour of the one star, or the 44 blue” colour of the other. 
