Engine Operating Temp. Question

["Ken Ross" <Kdross@email.msn.com>]

Where should the temperature gauge in a Silver Shadow II read?  In the
summer on a 90 + degree day the needle was reading at the VERY edge of the
upper solid white border of the gauge (this seems way to hot), and today in
50 + degree temperature the needle was reading at the VERY bottom of the
lower solid white border in the gauge (this seems to low).  What should a
normal reading be and why is there so much fluctuation with the temperature
gauge?  TIA.

Ken Ross