why have a conical lyne arm?

[swillbedone]

my wife saw my still and asked what that thing on top is. it's a lyne arm that tapers from the one inch pipe i have coming off the top of my still to the 3/8" pipe i have for the worm. i only did it for two reasons. one was because i could save that much money with out having to buy the reducers from a store and the other was that i think they look cool and they''re fun to make(i made a bunch of conical tin whistle designs out of copper a few years back so the concept is the same and i've got it down pretty well).

then she asked if that shape contributed something to the taste or operation of the still. i could not give her a good answer.

theoretically, is there a reason for that shape in stills other than to act as a reducer from still to worm?