In the early 90's the phone began to assume the shape in which it was to become familiar to Americans for the next 3-4 decades. This ancestor of the upright desk set was made in 1897. It was made of cast brass.

"Mr.Watson, come here; I want you!" These historic words, the first articulate sentence ever spoken over an electric phone, were uttered by Alexander Graham Bell when he spilled on his clothes some sulphuric acid which was part of the transmission apparatus. March 10, 1876, the receiver was a tuned reed.

"My word! It talks!" exclaimed Emperor Dom Pedro of Brazil on June 25, 1879 when he listened to the receiver of this early phone at the Philadelphia Centennial Exposition. Sir William Thomson (later Lord Kelvin) called Bell's invention "the most wonderful thing in America."

The round, camera-like opening on this box served as transmitter and receiver, needed mouth to ear shifts. Developed by Bell in the fall of 1876, it went into service in 1877 when a Boston banker leased two instruments which were attached to a line between his office and his home in Somerville, Mass. 
 

In 1877 Bell designed the first set with a combined receiver and transmitter that could be held in one hand. It was made of wood and resembled a dairy butterstamp, hence its name. It was in service when the world's first commercial switchboard opened in New Haven in 1878. 

People often became confused by using the same device for talking and listening, so a new feature was added- a second wooden transmitter-receiver.
You could use either for talking or listening, but you didn't have to move the instrument from mouth to ear. 

The Blake transmitter greatly improved telephone service. Here, its walnut case has been mounted on an adjustable stand to make one of the earliest desk sets. This instrument was invented in 1878 by Francis Blake, Jr. It emplyed carbon--a technique developed by Thomas Edison--and transmitted the voice with increased clarity.

The early telephones were voice powered. Then a wet battery was used which, though an improvement, sometimes resulted in acid on the carpet. Dry batteries came next. The fourth stage was the common battery, with the power supply at the exchange.

This more modern version of the telephone with a built in generator mechanism to provide cuttent for signalling the operator. Almost exactly similar phones were in genreral use from the late '90s through the '30s. Note enclosed receiver terminals. 
(some of these may still be in use in rural areas)