Ancient Pagan and Modern Christian Symbolism
by Thomas Inman, M.D. (1874)
Pagan and Christian symbolism

Figs. 29-32

Figures 29, 30, 31, 32, represent the various triangles and their union, which have been adopted in worship. Figure 29 is said to represent fire, which amongst the ancient Persians was depicted as a cone, whilst the figure inverted represents water.