What caught my attention here was the large lamp on top of the central column. It looked like something out of The Arabian Nights.

According to Douglas Keister in Stories in Stone. A Field Guide to Cemetery Symbolism and Iconography:

Because of the light emitted by it the lamp is a symbol of wisdom, faithfulness and holiness. In 2 Samuel 2, a lamp is a symbol for God.

28 And the afflicted people thou wilt save, but thine eyes are upon the haughty, that thou mayest bring them down.
29 For thou art my lamp, O LORD: and the LORD will lighten my darkness.
30 For by thee I have run through a troop by: by my God have I leaped over a wall.

I was unable to discover which of the Harris’s built the memorial, but quite a few of them have grave markers right in front of the balustrade including:

William Rees Harris (1855 – 1915)
Florence Mary Harris (1858 – 1919)
Ieuan Harris (1881 – 1940)
Laura Houghton Harris (1879 – 1925)
Gwendoline Matthews Harris (1887 – 1981)
Hugh Harris (1883 – 1899)
John Houghton Harris (1915 – 1954)