90th Anniversary of the Death of Alexander Graham Bell (Burundi 2012)

Souvenir Sheet 90th Anniversary of the Death of Alexander Graham Bell it reflects the thematic directions:

An aircraft (pl. aircraft) is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or the dynamic lift of an airfoil, or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes, rotorcraft (including helicopters), airships (including blimps), gliders, paramotors, and hot air balloons.Part 1 (Definitions and Abbreviations) of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that aircraft "means a device that is used or intended to be used for flight in the air."

Aviation is the practical aspect or art of aeronautics, being the design, development, production, operation and use of aircraft, especially heavier than air aircraft. The word aviation was coined by French writer and former naval officer Gabriel La Landelle in 1863, from the verb avier (synonymous flying), itself derived from the Latin word avis ("bird") and the suffix -ation.

Famous People refers to the fame and public attention accorded by the mass media to individuals or groups or, occasionally, animals, but is usually applied to the persons or groups of people (celebrity couples, families, etc.) themselves who receive such a status of fame and attention. Celebrity status is often associated with wealth (commonly referred to as fame and fortune), while fame often provides opportunities to make money.

An invention is a unique or novel device, method, composition, idea, or process. An invention may be an improvement upon a machine, product, or process for increasing efficiency or lowering cost. It may also be an entirely new concept. If an idea is unique enough either as a stand-alone invention or as a significant improvement over the work of others, it can be patented. A patent, if granted, gives the inventor a proprietary interest in the patent over a specific period of time, which can be licensed for financial gain. 

A telephone, colloquially referred to as a phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from Ancient Greek: τῆλε, romanized: tēle, lit. 'far' and φωνή (phōnē, voice), together meaning distant voice.

Telephony (/təˈlɛfəni/ tə-LEF-ə-nee) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the invention and development of the telephone.