I propose, in the present article, to lay before you some account of the means whereby the effects above referred to have been produced; of the manner and degree in which the public have availed themselves of these means; and of the improvements of which they seem to me to be susceptible.
In considering the means of inland transport, there are two distinct points to which I should solicit attention, viz, the road, and the power of traction or impulsion. A road is a contrivance by which the resistance opposed to a body moving on the surface of the earth, arising from the inequalities of that surface, may be diminished; and as it diminishes that resistance, in the same proportion does it accomplish its object. The power of traction or impulsion is efficient in proportion to its intensity, and the rate at which it is capable of exerting that intensity in reference to time. On the intensity of the power depends the resistance it can overcome, and this intensity is therefore proportional to the load. On the rate at which this power can be produced and exerted, depends the speed which is attainable by it.
The roads most commonly used are those of water, or canals; those of stone, or turnpike roads; and those of iron, or railroads. In all these species of roads, the first and most necessary quality is, that the line should be as nearly as possible level. As this, however, cannot be perfectly attained, there are contrivances peculiar to each kind of road, by which the difficulty attending the want of perfect level may be overcome. But as such contrivances constitute the greatest expense, whether in the original construction of the road, or in working upon it after it has been constructed, that course should always
