. The Romans constructed tracks consisting of
two lines of cut stones, and in the older Italian cities stone tracks
may still be seen in the streets, corresponding to wagon tracks, and
evidently designed for the purpose of rendering the movement of the
wheels easier.

The first rail tracks of which we have any knowledge were constructed at
the end of the sixteenth century. These rails, which were made of wood,
appear to have been an invention of miners in the Hartz Mountains. They
were the result of pressing necessity, for, as mines were usually so
situated that roads could only with great difficulty and expense have
been built to them, some cheaper sort of communication with the high
road had to be contrived.

After various experiments the wooden railway was adopted, and the
product of the mine was carried upon them to the place of shipment by
means of small cars. Queen Elizabeth had miners brought into England, to
develop the English mines, and through them the rail track was
introduced into Great Britain. Later the wooden rail was covered with an
iron strap to prevent the rapid wear of the wood, and about the year
1768 cast-iron rails commenced to be used. At the end of the last
century wheels were constructed with flanges, to prevent derailing.
More attention was also paid to the substructure, wood, iron and stone
being used for this purpose. Wrought-iron rails were patented in 1820.

The first authentic account of heat or steam engines is found in the
"Pneumatica" of Hero of Alexandria, who lived in the second century
before Christ. Hero describes a number of contrivances by which steam
was utilized as a source of power. Although these contrivances were at
the time of very little practical value, they are interesting as the
prototypes of the modern steam engine. The attempts to move wheels by
steam date back to the seventeenth century, when a number of experiments
were made, but their exact nature is not known, because they were all
soon abandoned, either on account of unsuccessful results or lack of
means. At the beginning of the eighteenth century Denis Papin
constructed a small steamboat, upon which he sailed in 1707 on the Fulda
River from Cassel to Munden, a distance of about fifteen miles.

The construction of locomotives engaged the attention of ingenious minds
a century and a half ago. It is claimed that Newton experimented with a
steam motor in 1680. Dr. Robinson described in 1759, in his "Mechanical
P