88 SCIENCE. 
i 
a ‘handle to facts,’ or as names of objects of which 
we have to speak, it seems desirable to have them so 
typographically distinguished that their presence on 
a printed page will quickly catch the eye as guide- 
posts to the subject of the immediate context. 
J. A. ALLEN. 
Cambridge, Mass. 
[The editor has yet to be convinced that typogra- 
phy should be moulded to suit the purposes of an 
indexer. | 
Eating horns. 
Indians eat the horns of the deer when in the vel- 
vet. One day on the Sioux Reservation, in Dakota, a 
deer was killed near camp, and brought in entire. At 
sight of it, Pahlani-ote, a Minneconjon of some fifty 
years, dropped his usual statuesque attitude, knocked 
off the horns, and, seating himself by the fire, began 
at the points to eat them, velvet and all, without 
cooking, as if they were most delicious morsels. The 
others of the party looked on as if they envied him. 
They said they always ate them so. S. GARMAN. 
Radiant heat. 
In a letter to Science of Dec. 21, 1883, Dr. Eddy 
has endeavored to show that I was mistaken in 
thinking that his proposed arrangement for proving 
that radiant heat is not subject to the second law of 
thermodynamics would not work. 
I can most easily explain how Dr. Eddy is again 
mistaken by referring to my diagram which he re- 
produces in his letter. Dr. Eddy says that every time 
the door z is opened two quantities of heat pass into 
the region B, one of which had originally come from 
A,and the other from B. I had assumed that the 
occasions when it opened to let heat that had come 
from A pass were different occasions from those when 
it opened to let that from B pass. I assumed this, 
because I could see no way of getting the heat that 
had come from B back again through z in the same 
direction as it had come out, except by a reflection 
from the back of y ; and of course that required y 
to be shut at the time of reflection, so that this heat 
could not reach z at the same time as any heat that 
had originally come from A. I have been unable to 
think of any method of getting the heat from A and 
what had come from B to travel simultaneously in 
the same direction; and I am inclined to think, that, 
if this were possible, Dr. Eddy’s doors, etc., would 
not be required to enable A to radiate more heat to 
Bb than B does to A. This supposed arrangement 
might, as far as I can see, go on working continuously, 
returning the heat to B, and simultaneously trans- 
mitting that from A; for this seems to me to be what 
Dr. Eddy postulates as possible. 
If the two quantities pass into B through z in two 
different directions, then two other quantities will 
escape from B in these two directions, and B will be 
in exactly the same condition as it would be accord- 
\ Ts 
[Vou. III., No. A. 
ing to my hypothesis that they passed into B at 
different times. { 
Dr. Eddy confesses to being unable to see how to 
accomplish what he postulates with my arrangement 
of screens and apertures; and I believe that the only — 
reason he is- unable to do so, and imagines that his — 
own proposed whirling tables would do so, is because 
my arrangement is so much simpler than his, that it 
is almost impossible to be misled as to where and 
when the heat comes in and goes out; while, with his 
arrangement, he has so many holes that it is almost 
impossible to keep before one’s mind all that is sup- 
posed to be going on. I cannot see how my simple 
arrangement is less general than Dr. Eddy’s compli- 
cated one, as it seems to me that a multiplicity of 
holes cannot be of any real use, while they produce ~ 
very serious complication; and, except in the number 
of holes, I think Dr. Eddy’s arrangement only differs 
from mine in that his supplies a mechanism for open- 
ing the apertures, which, of course, has nothing to 
do with the question. If Dr. Eddy will explain how 
he manipulates so as ‘‘ to bring the heat coming from — 
A into a position such that it would be in readiness to 
pass into B at the same time,”’ and in the same direc- — 
tion, ‘‘ as the heat which originally came from B is 
returned to B,”’ and does not rest upon the authority 
of Professor Gibbs that his arrangement does so, then 
I will agree that he has invented an arrangement by 
which the second law of thermodynamics may be 
cheated. Gro. FRAS. FITZGERALD. 
40 Trinity college, Dublin, : 
Jan. 7, 1884. f 
Professor De Volson Wood makes statements in his 
letter published in your issue of Jan. 11 which ap- — 
pear to me unsupported byfacts. Were yourcolumns ~ 
open to a lengthy discussion, I should like to show 
this in detail. Suffice it to say, that in his reference 
to Mr. Fitzgerald’s construction he entirely overlooks 
the difference between radiant heat, which must be ~ 
moving along given lines in a determinate direction, 
and other heat. The heat referred to as ‘ entangled 
in the space m n’ is radiant heat alone. I have defi- 
nitely traced its path, and shown that it does not 
move as Professor Wood states. Instead of regard- 
ing this fact, he has attributed to it the properties of 
heat as ordinarily existing in matter. 
Professor Wood also refers to his papers in the 
American engineer, etc. The only pointin that some- — 
what lengthy and personal discussion upon which I 
understand Professor Wood to finally insist, he re- 
published in the Journal of the Franklin institute for — 
May, 1883. In my reply in the same journal for June, — 
1883, I showed the fallacy of his objection. Sofaras — 
I know, Professor Wood has taken no notice of that — 
reply, and now completely ignores it. I may say that 
the proof he relied upon was of thisnature. He pro- — 
posed a certain construction or process (differing es- — 
sentially from mine) for dealing with radiant heat, 
and one which would not accomplish the end sought. 
He then showed that his construction was a failure, © 
and concluded that mine would therefore fail also, —a_ 
method of reasoning which seems to me inconclusive, 
to say the least. And now Professor Wood says that 
Mr. Fitzgerald’s construction is ‘conclusive.’ All it 
is conclusive of is, that it will not accomplish the end 
which I have proposed: we all agree that it will not. 
I have shown, however, that my proposed construc- 
tion differs from both in just those particulars neces- 
sary to make it accomplish the end sought. 
It is unfortunate that the velocity of radiant heat 
is such as to render experimental verification a mat- 
ter of great difficulty. H. T. Eppy. © 
