In message , Adrian D. Shaw
writes
Felly sgrifennodd
Norman Lynagh :
On the Weather Ships there were 3 ways of measuring sea temperatu

1. The canvas bucket method.
2. A tap on a pipe in the engine room. You turned on the tap and held
a thermometer bulb in the flow.
3. A thermistor somewhere in the intake pipework connected to a
readout in the Met Office at the stern of the ship.

They all gave different readings, with the bucket usually being the
lowest. There was a theory that the water in the bucket was cooled by
evaporation before the reading settled. I was never convinced by that.

Might the reason be that the bucket was filled by dangling it over the side
into the very top of the surface of the sea, whereas the others came from
pipework a little further below the surface?

Adrian

That could obviously explain why the readings were different but not why
the bucket was almost always cooler. As Martin said earlier in the
thread the intake water was probably warmed slightly before its
temperature was read.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England