INTRODUCTION.

15

ment; and which, it is trusted, will bethe means of elucidating- the true law ofsuch resistance.

Chapter VII.—Ropes being most gene-rally employed in dragging carriages upascents, or lowering them down from onelevel to another on Rail-roads, by the aid offixed steam-engines, or by the force of gra-vity, the friction of' these will form a sub-ject of enquiry of considerable importance.This chapter contains, therefore, a seriesof Experiments, on the friction of ropes,on several engine and self-acting planesin actual use; from which is deduced, atheorem for ascertaining the friction ofropes employed in dragging carriagesupon any Rail-road.

Chapter VIII.—Comprehends a set ofexperiments, observations, and deductions,