Final answer:
The horizontal bar on letters for visual balance should be placed slightly above the center, as similar adjustments are made in design and architecture like the positioning of columns.
Step-by-step explanation:
To achieve the appearance of stability, the horizontal bar on letters such as "B," "E," and "H" should be placed slightly above the center. This technique is related to optical illusion, a design principle which suggests that elements may look visually correct when they are not mathematically exact. Just as Beth mentioned regarding the placement of columns, where the ones on the edges are slightly closer to one another than those in the center, a similar adjustment is made to typographic elements to achieve a more balanced and visually appealing result.