
12 TECHNOLOGY. 
move carriages on arailroad. The first engine drew on the Merthyr-Tidwyl 
road five carriages of iron-ore weighing eleven tons, a distance of nine 
iles in 1? hour. At the same time Oliver Evans constructed a locomotive 
in the United States, but it was not until 1824 that Stephenson built the first 
successful locomotive for the Stockton and Darlington railroad, by which 
at length passengers were transported in 1826. It still remained doubtful 
whether preference was not due to the employment of stationary steam- 
engines, until in 1829Stephenson’s locomotive ‘“* Rocket ” was victorious in 
all trials. When in 1830 the Liverpool and Manchester railroad succeeded 
beyond expectation, and Stephenson’s tubular boilers proved to be as safe as 
advantageous, the railroads at once rose to that high degree of importance 
which has ever since continued to increase. From that time no branch of 
industry has been so much the object of new inventions as railroads; the 
most ingenious men surpassed themselves in constantly adding new improve- 
ments to their engines. Self-acting inclined planes and stationary steam- 
engines were employed for overcoming steep grades, and new forces were 
sought in order to replace steam by a less expensive motive power, of which 
however atmospheric pressure was the only one practically attempted, in 
1839, but has since been abandoned. 
After England the United States were the first to introduce railroads 
with locomotive steam-engines. The first railroad in France was that from 
St. Etienne to Lyons, built in 1827; in Germany that from Nurnberg to 
Firth, in 1835. Since then railroads have been constructed in all the 
European States, and in a few years a connected system of railways will 
be spread over all Europe. 
After this brief historical review we will now proceed to treat of the 
construction of railroads and the motive power employed on them. 
1. Location oF A Ratroap. ‘The location or first determination of a 
railroad line is a matter of the greatest importance, as the success and value 
of the work are in a great measure dependent on a judicious selection of the 
line, and the highest qualities of talent and knowledge are required in the 
engineer who undertakes the task. The considerations that must mainly 
guide in the location are, the object of the road, the grades and curvatures, 
the physical conditions of the country, and the relative cost of the road in 
different locations. 
The objects of railroads may be various. A main line which is intended 
to connect distant parts of a country and to serve as a basis for a system of 
branch roads which are to intersect the country in every direction, will be 
made to pass through the most important places only, pursuing its general 
direction without reference to minor towns. If a road in a sparsely popu- 
lated country is intended to serve as a means of promoting its colonization, 
the physical conditions of the country will be the prevailing consideration, 
and the road will pass through those regions the agricultural or mineral 
products of which promise the greatest success. Again the object of a road 
may be to transport passengers and freight by the same power as rapidly 
as possible from one terminus of the road to the other; in this case the 
straight direction of the road would be a main condition, which, however, 
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