Primary Source

Description of Collection:
Over six thousand letters, which include drafts, fair copies and carbons of Bohr's replies. The correspondence covers the development of quantum and nuclear physics. Correspondents include:

Hans Albrecht Bethe, Patrick Maynard Stuart Blackett, Felix Bloch, Harald Bohr, Max Born,
Christian Christiansen, Dirk Coster, Marie Curie, C. Cuthbertson,
Charles Galton Darwin, B. Davis, P. Debye, Max Delbrück, Paul Adrien Maurice Dirac, W. Duane,
Paul Ehrenfest, Albert Einstein, W.M. Elsasser, Poul Sophus Epstein,

A collection of some 25,000 historical photographs, slides, lithographs, engravings, and other visual materials, the Emilio Segrè Visual Archives is part of the Niels Bohr Library of the Center for History of Physics at the American Institute of Physics. The collection focuses on American physicists and astronomers of the twentieth century, but includes many scientists in Europe and elsewhere, in other fields related to physics, and in earlier times.

Historic Pittsburgh is a digital collection that provides an opportunity to explore and research the history of Pittsburgh and the surrounding Western Pennsylvania area on the Internet. This website enables access to historic material held by the University of Pittsburgh's University Library System, the Library & Archives of the Historical Society of Western Pennsylvania at the Senator John Heinz Pittsburgh Regional History Center, and the Carnegie Museum of Art. The project represents a model of cooperation between libraries and museums in providing online access to their respective materials.

The Social Welfare History Archives has acquired over 200 collections of organizational records or personal papers. The collections chronicle the development of a broad range of activities. Included are the classic social services offered to particularly vulnerable classes of persons, e. g., the economically dependent, recent immigrants, migrants and refugees, unwed mothers, abused and abandoned children, the aged, and the developmentally and physically challenged. Beyond these are causes and services aimed at the broader community, many of them not traditionally included in a narrow definition of social welfare: child-rearing advice for parents, recreation programs, community planning, arts programs, preventive health, and family planning. Because of the problem-solving mindset of the service field, the collection as a whole tends to stress times of crises. Coverage is richest in--but not limited to--times of war, depression, or other types of social and economic dislocation.

Tutankhamun: Anatomy of an Excavation is ambitious in its scope but simple in its aims: to make the complete records of Howard Carter's excavation of the tomb of Tutankhamun available on these web pages. It is astonishing, but no longer acceptable, that some eighty years and thousands of articles, hundreds of books, and dozens of exhibitions after the discovery of the tomb, this most famous event in the history of Egyptian archaeology has not yet been fully published.

Airshipsonline houses the online archive of the Airship Heritage Trust. Inside you will find an extensive history relating to all of the British Airships from 1900 to the present day. The OnLine-Forum is open to to offer comment and share in news and knowledge between members and the public who share in the interest of lighter than air travel. The Trust is a charitable voluntary run organisation based in the U.K. We own and are responsible for the national heritage airship archive and large collection of airship artifact's and photographs relating to the British Airship Programme, from it’s early days at the turn of the century to the Skyships of the 1980’s.

Gentlemen:
It gives me great pleasure to be enabled to report the Niagara Suspension Rail Way Bridge complete in all its parts. The success of this work may now be considered an established fact. The trains of the New York Central, and of the Great Western Rail Road in Canada, have been crossing regularly since the 18th of March, averaging over 30 trips per day.
One single observation of the passage of a train over the Niagara Bridge, will convince the most skeptical, that the practicability of Suspended Railway Bridges, so much doubted heretofore, has been successfully demonstrated.

In developing the STRUCTURAL ENGINEERING SLIDE LIBRARY as a comprehensive resource for teaching structural and architectural engineering at college and university level, I felt there was a need to devote a volume to the work of one structural design company. Leonhardt, Andrä and Partners of Stuttgart, Germany, was an ideal choice for this project. One of Europe’s leading structural design companies, its staff has been on the leading edge of many developments in engineering over the past 40 years. Their name has been particularly associated with the development of incrementally launched bridges, cable-stayed bridges, cable-net structures, and prestressed concrete television towers.

From southeast to northwest, Cleveland is traversed by the winding Cuyahoga river valley, which, while it provides the railroads with an effective entrance to the city, cuts it into two distinct districts as far as vehicular traffic is concerned. To provide crossings over the river and its wide valley, several bridges have been builds, notably the Detroit-superior Bridge near the lakefront and the central viaduct to the south. After 25 years of study on viaduct to connect Lorain avenue on the west of the river with the district to the east, in The Course of which time the project was once abounded after bonds had actually been voted for construction, the citizens of Cleveland are opening, the first week in the November, a $6500000 viaduct 5,865 ft. long, with its eastern terminus at central avenue. Dr. Watson's interest in the project has been continuos since its inception.