218 F. A. P. Barnard on the Zodiacal Light. 
the observer seemed to have entered on his task; and the reso- 
lute determination displayed by him to ascertain, first of all, the 
acts, ho matter to what conclusions they might lead. ‘The con- 
clusions, however, to which they have led in the mind of Mr. 
Jones himself, and apparently in the minds of most of those who 
had the pleasure of ‘istening to his explanations, are attended, as 
the writer is forced to believe, with some difficulties, which it is 
the design of this communication to set forth. These difficul- 
ties would have been brought to the notice of the Association, 
during the meeting, but that the authority by which the theory 
of Mr. Jones was so immediately and so emphatically endorsed, 
presented a front too imposing, and too entirely undivided, not 
to induce hesitation, and awaken some distrust of objections 
which were then but the suggestions of the moment. Reflec- 
tion, however, has had no other result but to confirm the convic- 
tions of the writer in the validity of those objections; and it 1s 
on this account that they have been finally reduced to the pres- 
ent form, in the hope that, if they are ill-founded, their fallacy 
ositions. 
1. The light, whatever be its source, cannot proceed from ® 
body enveloping the earth. 
2. It cannot proceed from a body eoncentric, whether as 
$a ring, with the sun, and interior to the earl 
an 
h’s 
pte a 
3. It eannot proceed from a ring concentric with the sun and 
exterior to the earth’s orbit. lv- 
_ 4. It cannot proceed from a nebulous planet or comet, revorv 
hat of the 
mat the sun in an orbit either wholly interior to t 
‘wholly or partly exterior. 
* Mr. Jones regards it as a specular reflection.—Eos. 
i * i eile ge 
5 Oe eae aes 
