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.
Expository writing is a type of writing where the purpose is to explain, inform, or even describe. It is considered to be one of the four most common rhetorical modes. The purpose of expository writing is to explain and analyze information by presenting an idea, relevant evidence, and appropriate discussion.