18 b 
Annual Meeting, April 25th, 1871. 
E. W. Binney, F.R.S., F.G.S., President of the Section, 
in the Chair. 
The following gentlemen were elected Officers of the 
Section for the ensuing year : — 
JOSEPH BAXENDELL, F.R.A.S. 
^iK-^rtsibtnls. 
E. W. BINNEY, F.R.S., F.G.S. | ALFRED BROTHERS, F.R.A.S, 
JStmifttg. 
a. Y. VERNON, F.R.A.S., F.M.S. 
Srnmtrcr. 
THOMAS CARRICK. 
“ Performance of the Electro-Magnetic Engine,” by the 
Rev. H. Highton, M.A. 
1. I am sure that Dr. Joule is a sufficient lover of truth 
not to feel offended if I submit his last explanations on this 
subject to the test of facts and experiments. 
Not having myself the means of trying experiments 
with sufficient accuracy to venture to publish results, I will 
make use only of M. Favre’s and Dr. Joule’s own experiments. 
2. The whole basis of Dr. Joule’s new reasoning is, that 
when a magnetic engine works rapidly, less heat is evolved 
and more absorbed in it. Taking his own figures as a basis, 
I find he calculates that when the current is reduced to 
one-half what it was when the engine was at rest, the heat 
evolved per hour would be one quarter, and per equivalent 
of zinc consumed one half. Now let us take the measure- 
ment by M. Favre’s calorimeter (“ Comptes Rendus,” vol. 
XLV.) When the engine was at rest, the calorimeter in 
which it was placed showed, per equivalent of zinc con- 
sumed, 2,219 heat-units. When it worked slowly, raising a 
