102 The Planet Ma/ts : a Fragment 



The contraction of the snow was very obvious in this series 

 of observations, and will be traced in the drawings if they are 

 examined in the order of time and not of position. Aug. 14. 

 I had caught it even with a power of 55. Sept. 29. I thought 

 it " much less conspicuous." Oct. 8. It was a " very minute 

 speck." Nov. 4. I estimated it, from memory, at not more 

 than 1"*5. The sharp definition of the disc that night permitted 

 me to see with a power of about 800, what I had seldom been 

 able to satisfy myself about, that the white ellipse was all within 

 the limb, and as I believed not even in contact with it. The 

 following night I noticed that the snow was not more than one- 

 twentieth of the diameter (afterwards found to be 17"*5), and 

 could not exceed 1". With regard at least to the region of the 

 dusky fan, and the antarctic circle, I think it appears that there 

 was considerable more open sky in Mars in 1862 than in 1830. 



Some observers have noticed a luminous border around the 

 limb, and considered it as an indication of a dense atmosphere. 

 This never caught my attention. Nov. 4. " I looked for a 

 luminous ring round the limb, but could see none. The great 

 spot (Fig. VI.) extended close to the limb, if not to absolute 

 contact." Nov. 5 and 6. The markings in general reached the 

 limb, and there was no luminous circumference. Dec. 10. 

 Fig. VII., " The darkness of the end of the band near the pole 

 is decided close to the limb." At other times I have thought 

 that the spots became much less visible near the edges of the 

 disc, as was usually remarked by Beer and Miidler ; but it is 

 not always easy to distinguish between perspective foreshort- 

 ening and atmospheric obscuration. 



Nov. 22. A bright border, as in Fig. XIII., was repeatedly 

 suspected to attend the N. edge of the dusky band G., then 

 lying centrally across the disc. It was, however, much less 

 luminous than the snow-spot. It will be observed from the 

 drawings that on this side of the globe there were repeated 

 traces of faint shadowy markings in the N. hemisphere. Nov. 

 11 ! . Fig. XI. " There seems to be a large amount of minute 

 detail over the N. part of the disc, quite out of my reach : the 

 whole is painfully woolly, though the limb is clear." 



Oct. 11. I noticed for the first time a patch of bright green 

 light, occupying an arcof 40° or 50° S. from the equator along 

 the following limb, or terminator. I saw it again, more or less, 

 on Beveral occasions in the course of the next month, and pro- 

 bably might bare perceived il before, had 1 more frequently 

 used the higher powers, which almost exclusively rendered it 

 visible. I was prepared for aothing of the kind, and had not 

 thought of MiidN t's Bimilar observations in 1841 with the great 

 Dorjini achromatic. It is probably merely an optical deception. 

 but nothing of this kind should pass unnoticed, 



