94 REPORT—1849. 
such sidings are rusting most rapidly ; it is the sides of the rail I hold to as 
proof, as such sides are in both cases removed from any friction. I may also 
= Siding 
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name that even the keys and chairs partake of the rusting or non-rusting in- 
flence, as the case may be. 
“I have had no means as yet to ascertain whether my conjecture is right or 
otherwise; but I consider the rolling of the wheels in one direction to confer 
or induce a magnetical condition on the rails, in the same manner as in the 
case of inducing magnetism or magnetical property on a piece of iron or 
steel, by the ordinary method of passing the parent magnet along the iron 
bar, thus: 


Fig. 4. 
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The subject is, I think, a very interesting one, and well-worthy of attention, 
as it may tend to illustrate, on a most grand scale, some of the pure results 
of the delicate investigations which I doubt not you are familiar with, both as 
to what has been brought to light by others as well as yourself. If there 
be any further questions I can answer, you may command me at all times, as 
“Tam most sincerely yours, 
“ Robert Mallet, Esq.” “ James NASMYTH.” 
The Ulster Railway between Belfast and Portadown, which was at that 
time a single line on the wide gauge, with a bridge rail of 52lbs. per lineal 
yard as per fig. 5, half-sized section given, and without any chairs, and resting 
Fig. 5. 
za 
on longitudinal wood sleepers, presented an excellent position for this expe- 


