The challenge facing the signal industry was achieving the same level of safety and reliability that was inherent to purely mechanical systems. An experimental hydro-pneumatic interlocking was installed at the Bound Brook, New Jersey junction of the Philadelphia and Reading Railroad and the Lehigh Valley Railroad in 1884.
This is an example of an expository paragraph   In 1997, 175,000 volunteers picked up three million pounds of garbage along the coasts of the United States. As a result, bo â¦ th people and sea animals can enjoy cleaner and safer environments.
An Expository Essay is a piece of written work that aims to define and investigate a topic for the reader. This can be accomplished in several ways: defining a term, comparing and contrasting, analyzing a cause and effect, etc. The main objective is to prove a thesis through factual evidence.