176 A VOYAGE OF DISCOVERY 
any means to be so sensible after the thermometer 
has fallen to between 30° or 40° below zero. 
We had a good instance to-day of the effect that 
different colours have in reflecting heat, for the 
piece of board on which the thermometers were 
suspended had one side of it painted black, and 
the other side white, that is of the colour of the 
wood itself, and it was observed that the ther- 
mometer suspended on the black side, never 
fell lower than 52°, while the one that hung 
on the white side of the board stood at 54°.* I 
remarked also at this time that the smoke 
from the ships rose quite perpendicularly, (there 
being no wind at the time,) so that a low tem- 
perature alone does not appear to be sufficient to 
produce the phenomenon of smoke falling to the 
ground as some have observed, but which I must 
confess I have never seen myself, although I have 
frequently, during this winter, looked out for it. 
I have observed, indeed, two or three times, 
that the vapour from the coppers, when they 
were melting snow, condensed, and fell immediate- 
ly it came into the open air; but this is easily ac- 
counted for, nor could indeed any thing else be 
expected than that aqueous vapour would, on 
coming into a temperature of thirty or forty 
“degrees below zero, immediately condense, and 
consequently fall. 
Tuesday, 15th. — At six o’clock this morning 
* As the piece of board on which they (thermometers) were 
suspended, was set up on the ice at a considerable distance, 
(perhaps from 80 to 90 yards) from the ship, we are certain 
that this difference could not be caused by any locality, or 
substance that was near it. 
