Why the bottom of flame is wider than its edge?

The candle can be wax or oil. As we know the candle is light source , we will do a small analysis on that. Lets consider the wax candle in our cases. The candle is lighted by heat of the match or other candle flame. Prior to candle being ignited, The wick is saturated with fuel in its solid form and the wax first melts into fuel form then it vaporize a small amount and mix with oxygen to form flame. The heat of the flame melts the top of the solid wax, the liquefied fuel moves upwards through the wick via capillary action.

Here, The vaporized wax has higher atom movements, as well the vaporization starts from bottom to top, the atoms are higher in bottom of the flame than its edge.

Test Vaporization:
Ignite two candles, then blow out one candle, after the blowing out, immediately we can see the the white gas flow in the air, just bring the another candle near to that gas air, that candle ignited very fast, since that gas is nothing but the vaporized wax.