Sune t, 1871] 
NATURE 
33 



the surface of the body. I did not, however, ignore that law, 
andI have taken it into account when speaking of Prof. Kirch- 
hoff’s discoveries. But here it was quite out of place to refer to 
it. Indeed, the consequence of this law is that a body may 
have a very high temperature, and yet radiate but very little ; but 
the law does not state that a body may radiate more than its 
own temperature allows. When we judge, therefore, of the 
temperature from the radiation, we certainly commit an error; 
but so we always judge the temperature from one part of the 
effect that it is capable of producing ; and taking into account the 
law of Dulong, we should find even a higher temperature in 
reality in the radiant body, as is the case with the gases. 
The conclusion, therefore, to which I have arrived, after Mr. 
Waterston, is, I think, by no means-excessive, but if there is an 
objection possible to be made, it is exactly in the direction opposite 
to that of my reviewer. Certainly this conclusion is at variance 
with that of M. Zollner, but it agrees with the results of other 
observers. This high temperature besides is really a virtual 
temperature, as it is the amount of radiation received from all 
the transparent strata of the solar envelope, and this body at the 
outer shell must certainly be at a lower temperature. 
But this does not prove the incorrectness of my proposition that 
a thermometer dipped inside the solar envelope in contact | 
with the photosphere, would indicate the enormous temperature 
that Mr. Waterston has found for the first time. 
P. A. SECCHI, 
Director of the R. College Observatory 
WILL you permit me to make a few comments on Prof. New- 
comb’s review of my treatise upon the Sun. 
Soon after the work had appeared, I was informed that the 
account I had given of Mr. Stone’s treatment of the transit ob- 
servations in 1769 was not such as Prof. Newcomb would admit 
to be just. Knowing how much attention Prof. Newcomb has 
given to this subject, and his great skill as a mathematician, I 
was prepared to learn that I had misapprehended some points of 
the discussion between himself and Mr. Stone. I do not even 
now know to what specific statements of mine he objects ; but 
he may rest assured that my sole object has been, and is, to give 
a just account of the matter. My account is in agreement with 
that given by Sir John Herschel, and by Admiral Manners when 
the Gold Medal of the Royal Astronomical Society was pre- 
sented to Mr. Stone. I had also inferred from the nature of the 
discussions between Mr. Stone and M. Faye, and between Mr. 
Stone and Prof. Newcomb, that the truth lay much as in my 
narrative. At any rate, those who were present at the meetings 
of the Royal Astronomical Society in 1869 and 1870 will scarcely 
think that I have been led by any personal prejudices to advocate 
Mr. Stone’s cause with undue favour, for Mr. Stone’s strictures 
on some of my papers, and especially on papers relating to the 
subject of the transits of Venus, were severe even to bitterness. 
I believe that Prof. Newcomb’s mastery of this special subject 
is calculated to prevent him from rightly judging my treatment 
of it. He sees it from too near a stand-point, and therefore un- 
duly enlarged. Tam sure that on a careful reconsideration of the 
matter he will feel that I could not have given a fuller account 
of it than I have, without spoiling the symmetry of my book. 
Already a seventh part of the letter-press and more than a third 
of the appendix (besides three plates and twenty-four diagrams) 
have been given to the subject of the sun’s distance. I do not 
think that more space could very well have been spared. It re- 
mains yet to be proved that a single statement in these pages is 
inaccurate. I deny confidently that the distortion of the limbs 
of Venus and Mercury in transit has been froved to be the pro- 
duct of insufficient optical power. Irradiation must produce such 
effects to a greater or less extent ; and I renew ‘“‘gravely”” my 
proposal to measure the effect, whatever its cause or causes, 
during the next transit. I would remind Prof. Newcomb that 
every observer at Greenwich noticed the effect (more or less) 
during the transit of Mercury in 1868. Now the Greenwich in- 
struments are not commonly supposed to be utterly imperfect, 
nor the Greenwich observers wholly unskilled. Even if we ad- 
mitted both these points, I should still adhere to my proposal. 
For I have shown in the Monthly Notices of the Royal Astro- 
nomical Society for 1870, that those two observations which 
differed most widely are brought into perfect agreement when the 
relative breadth of the black ligament observed in each case is 
taken into account, 


Prof. Newcomb has misunderstood my remarks about the D 
line in the spectrum, I haye never concluded, and certainly I 
have nowhere stated, that ‘‘the light of the sodium lines proper 
is reduced.” What I have pointed out is that where those lines 
fall on the spectrum of the electric light, and where, therefore, 
we should expect an increase of light, there seems to result dark- 
ness. In p. 118 I amcareful to use in one place the word seem, 
in another the word affear. 
I must remind Prof. Newcomb that three countrymen of his 
own, Professors Harkness, Curtis, and (quite recently) Young, 
have supposed, with me, that the theary as been maintained, 
that the light of the corona is due to sunlight directly illuminating 
our atmosphere, and that they and Mr. Baxendell have opposed 
that theory as pointedly as I have. 
I have, however, to admit that some passages ‘‘ indicating 
personal feeling ” would have been better—much better—omitted. 
Ishould have remembered that the explanation of such personal 
feeling would be unknown to most of my readers. Those who 
know that because I advocated opinions respecting the corona, 
which are now all but universally admitted to be just, I was 
spoken of as ‘‘simply making myself ridiculous,” will at least 
acquit me of responding as rudely as I had been attacked. But 
the generality of my readers had heard nothing of this and other 
assaults upon me. 
I take this opportunity of noting that Dr. Armstrong, of the 
London Institution, has shown me that in my account of the re- 
searches of Mr. Lockyer and Dr. Frankland I have not done the 
former justice. Some alterations must be made also in my 
narrative of the work of Dr. De la Rue and P. Secchi in Spain 
in 1860; much more of the credit of the results then obtained 
being due to Dr. De la Rue than I had judged from the narrative 
in P. Secchi’s ‘‘ Le Soleil.” Also the enunciation of the aurora 
theory of the corona must be assigned to Prof. Norton of 
America. RICHARD A, Proctor 
[With respect to the penultimate paragraph of the above letter, 
we need only refer to our own comments on two previous letters 
from Mr. Proctor, under date July 7 and August 4, 1870, which we 
now reprint. Ep.:—‘‘For an accurate though incomplete 
statement of Dr. Frankland’s and Mr. Lockyer’s theory of the 
Corona, we refer our readers to the first number of NATURE. 
Many of them will not be surprised to find that it is of what 
Mr. Proctor states it to be. Dr. Frankland and Mr. Lockyer, 
from their laboratory experiments, have shown that the pressure 
at the base of the chromosphere is small, and they have there- 
fore stated that it is scarcely possible that a very extensive atmo- 
sphere lies outside the chromosphere. Mr, Lockyer has shown, 
moreover, that the height of the chromosphere as seen by the 
new method probably falls far short of its real height as seen 
during an eclipse as it was seen by Dr. Gould. A reference to 
the same number of this journal will also show that Mr. Proctor 
has misrepresented Dr, Gould’s statements, which endorse the 
idea put forward by Dr. Frankland and Mr, Lockyer. Dr. 
Gould has expressly stated ‘that there were many phenomena 
which would almost lead to the belief that it was an atmospheric 
rather than a cosmical phenomenon.’ This is an opinion held 
by Faye and other distinguished astronomers, and Mr. Lockyer 
has simply shown that should this turn out to be the case, the 
continuous spectrum observed may be explained. Astronomers 
did not require Mr. Proctor to tell them what he has recently 
been enforcing ; but, more modest than he, they have been wait- 
ing for facts, and Mr. Proctor surely is old enough to see that by 
attempting to evolve the secrets of the universe, about which the 
workers speak doubtfully, out of the depths of his moral con- 
sciousness, he simply makes himself ridiculous, and spoils much 
of the good work he is doing in popularising the science.” — 
‘* Still holding to our comments, we gladly state that they were 
not written in the spirit in which Mr. Proctor has read them. 
He is known to all as an astronomical worker, and our objection 
to his mathematical result was that it was based upon data among 
which the principal point at issue was accepted as proved.” ] 
Rain after Fire 
In Paris, on Wednesday the 24th inst., after describing the 
terrible conflagrations, one of the correspondents writes thus :— 
*«A more lovely day it would be impossible to imagine, a sky 
of unusual brightness, blue as the clearest ever seen, a sun of 
surpassing brilliancy even for Paris, scarcely a breath of wind to 
ruffle the Seine. Such of the great buildings as the spreading 
