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A paper was read by J. C. Dyeb, V.P., “ On the Nature 
of Friction in Mechanics/’ in which he stated that: — 
Resistance to motion by surface contact arises from distinct 
kinds of obstruction, according to the nature of the moving 
bodies and to the condition of their surfaces. These present 
problems that have been investigated by many writers and 
experimenters ; but no fixed law or rule has been discovered 
for measuring such resistances as applied to different kinds of 
friction. The inquiries have mostly related to the action of 
solid surfaces, and some approach to the measure of their 
resistances has been attained, by finding the relation of falling 
weights to those sliding over horizontal surfaces of different 
kinds of woods, metals, glass, marbles, &c. ; but little or 
nothing has been accomplished towards showing the nature 
of the surface resistance to solids moving through water or 
other liquids. The experiments of Captain Beaufort and 
Robert Fulton afford data for the sum of such resistance, but 
not for its mode of action. 
In the case of solids, if the surfaces in contact were perfectly 
level and hard, they would slide over each other without 
friction; but as none such are known, their resistance to 
motion arises from the projecting points and indentations, 
which grapple with more or less force, causing the moving 
body to rise and fall and to abrade and wear down the sur- 
faces ; thus gravity and cohesion constitute the counteracting 
or compound force called friction. In railway wheels, as 
small portions of the peripheries are in contact with the rails, 
when both are in good order but slight resistance is offered ; 
but even in this case the common measure of the weight into 
the distance does not strictly apply, and the amount of tractive 
power is obtained from experience only. This retarding 
