114 
Small print was easily read at a considerable distance, 
without any reflector behind the light. The cost of a 
battery of 100 pairs will be about £4, whilst one of equal 
power with platinum negatives would be £60 or £70. 
The powers of the battery were tested by many brilliant 
experiments — as the ignition of great lengths of thin wire, 
the combustion of metals, the electric light, and the dis- 
persion of that light by the prism. 
In the course of the discussion which followed, Mr. 
Pearsall, in an interesting speech, alluded to the great 
importance which might accrue to the public, and especially 
in saving the lives of mariners, if the adoption of this mag- 
nificent discovery were brought into use in lighthouses, or 
sent out in steam vessels on particular occasions, as foggy 
weather, &c, to guide ships on dangerous parts of the 
coast ; and hoped that no argument of such a paltry or 
disgraceful character as expense would interfere to prevent 
so benevolent a project being carried out. 
Mr. W. S. Ward supported the proposal of Mr. Pearsall, 
with additional suggestions as to its applicability, and the 
means of recognising the different lighthouse stations, by 
the number of lights employed, &c. ; also on the compara- 
tive cost per hour of a light such as Mr. Dresser had 
exhibited, as weighed off by a galvanometer in the room ; 
and showed the fallacy of supposing this light, however 
beautiful, would ever supersede the ordinary gas for shops, 
streets, &c. 
ON SOME PHENOMENA OF DIA-MAGNETISM, WITH EXPERI- 
MENTS. BY WILLIAM SYKES WARD, ESQ., OF LEEDS. 
In the course of some experiments, in which I was desirous 
of exhibiting the principal phenomena of Dia-Magnetism, 
