Capital
The enlarged head of the supporting column of a flat slab is called a capital. The capital is an important architectural element that serves as a transition between the column and the horizontal elements it supports. Here are some key points to understand about the capital:

Function
- The primary function of a capital is to distribute the load from the slab evenly onto the column.
- It also serves an aesthetic purpose, providing a decorative element at the top of the column.

Design
- Capitals can come in various shapes and styles, depending on the architectural design of the structure.
- Common capital designs include Doric, Ionic, and Corinthian styles, each with its own distinctive features.

Construction
- Capitals are typically made of stone, concrete, or other durable materials that can support the weight of the slab.
- They are often intricately carved or molded to add decorative details to the column.

Importance
- Capitals not only provide structural support but also add visual interest to the overall design of a building.
- They help to create a sense of proportion and balance in architectural compositions.
In conclusion, the capital plays a crucial role in both the structural integrity and aesthetic appeal of a building, making it an essential element in architectural design.