Referee report by A. Gray on 'The Mechanism of the Electric Arc' by H. M. Ayrton

                                Royal Society,
Received 3-Dec.1901
<u>Confidential <\u>
Referee’s Report 
To the Sectional Committee for Physics and Chemistry 
Paper by Mrs H. Ayrton 
On the Mechanism of the Electric Arc.
1. Whether the paper should or should not be published in 
“Philosophical Transactions “
<u>The paper should be so published .<\u>
2. Whether it should be published in full or in part only.
<u>In full <\u>
3. Whether any modifications are necessary or desirable and 
if so of what nature.
<u>No modifications seem necessary.<\u>
4. What illustrations (if any) accompanying the paper 
should be reproduced.
<u>The illustrations are not excessive and should 
I think all be given.<\u>
The paper seems to me a very suggestive 
one, and to throw much light on the much 
debated questions of the mechanism of the arc,
or rather as I should put it on the physical 
processes concerned in the production of an electric 
arc. There is as I have noticed elsewhere 
some apparent divergence of result as to the 
existence of a back electromotive force in the arc,
between this paper and Mr. Duddell’s on the same subject 
Mrs Ayrton is of opinion that great heat is 
developed in a film of great resistance close to 
the positive carbon, while Mr. Duddell detects an 
opposing potential difference. It is true that Mr.
Duddell as I understand him distinguishes between an opposing <s>E.M.F.<\s> difference of potential and 
a “back E.M.F.” but I do not understand the distinction.
Professor A. Gray.