Does city improvement really work?

[planetfall]

Finally questioning mining and irrigation and really work.

At first I thought the value of mines and irrigation depend upon city size. But now not sure.

Given: every tile inside the city 21 tile border goes into annual civ production.

But, what if city has grown to size 3, do any tiles outside 2 tiles from city center get added?

Other way of asking question, if put
mine in tile M, will it generate any gold?


m c c c m M m c c c m
c c c c c M c c c c c
c c X c c M c c X c c
c c c c c I c c c c c
m c c c m G m c c c m

c= city tile
X= city center
I= irrigation
G= gold
M= mine

If doesn't does this mean we need to
either put a colony or a city boundary
around all gold resources?

[Gramphos]

A mine desn't do a thing unless worked on by a citizen, so a mine outside 21 tiles radius is useless.