Memory (1913-1914) by Augustus Lukeman, for the Ida and Isidor Straus Memorial, Straus Park, Manhattan, New York City

2. Landmarks Can Change Over Time

By Gene Stavrou
April 2022

Treebase's data structure is meant to model the real world with an eye toward generating insights and visualizations. The database itself is made up of two basic constructs. NODES represent people, places, things, and ideas. EDGES describe relationships between nodes. This month we'll be defining characteristics of the LANDMARK node type (used to describe buildings, natural landscape features, works of art, and other objects) and its relationships. A building and its architect, for example, have the relationship "[building name] designed_by [architect name]," where designed_by is the edge between the building and architect nodes.

Although a landmark can be built on a foundation or rooted to the ground, its context can change over time. The landmark node type and its related edges must be able to note that context. We'll use real-world scenarios as use cases to create the language for describing landmark nodes and relationships.

Succeeded vs Replaced

We'll start with a particularly historic New York City building: the second Madison Square Garden (MSG2), built in 1890 on the site of the first Madison Square Garden (MSG1). Image: The second Madison Square Garden. MSG2 was demolished in 1926 to make way for the new headquarters of The New York Life Insurance Company (NY Life HQ), which stands on the site today. MSG3 was built farther uptown.

In our database, we'll need to differentiate between a building's next incarnation (what succeeded it) and what took its place on its site (what replaced it). In shorthand, we'll write

[MSG1] succeeded_by [MSG2]
[MSG1] replaced_by [MSG2]
[MSG2] succeeded_by [MSG3]
[MSG2] replaced_by [NY Life HQ]

The previous NY Life Headquarters (The "Clock Tower" Building) still stands on 346 Broadway.

[NY Life Clock Tower] succeeded_by [NY Life HQ]