ON THE TEMPERATURE AND MOVEMENTS OF 
THE DEEP SEA. 
By Dr. W. B. CARPENTER, F.R.S. 
BEING THE SUBSTANCE OF A LECTURE DELIVERED BEFORE THE 
PHILOSOPHICAL SOCIETIES OF LEEDS, BRADFORD, AND NEW- 
CASTLE-ON-TYNE, IN FEBRUARY 1872. 
U NTIL a recent period, the bottom of the Deep Sea has been 
— if I may make use of an Irish 66 bull ” — an unknown land 
to us ; for the means of research into its condition were very 
unsatisfactory. For example, in the first place, with regard to 
temperature. If we let down a self-registering thermometer, 
which should give the lowest or the highest temperature which is 
there encountered, there is this source of error in the indications of 
the thermometer — that the enormous pressure of the water upon 
the glass bulb will very probably so alter the shape of the bulb 
as to force up the mercury in the tube, so as to cause it to 
register a temperature several degrees higher than that which 
it actually encountered. Now it has only been recently — 
through the ingenious contrivance of my late excellent friend, 
Professor Miller, of King’s College — that this difficulty has 
been overcome. We found, on putting thermometers of ordi- 
nary construction into the water-chamber of an instrument 
constructed on the principle of the Bramah press, with a 
powerful force-pump that should subject these thermometers to 
pressure of any amount up to three tons to the square inch, that 
the very best instruments that had been previously relied upon 
were raised from eight to ten degrees by the pressure of the 
water forced in; and we found that inferior thermometers, such 
as had been used in many deep-sea soundings on former occa- 
sions, were raised from twenty to fifty degrees. So that you 
see there is no reliance to be placed on any previous deep-sea 
soundings as to temperature, except in this, that we know that 
the error of their thermometers could not have been less than 
a certain amount. For instance, when Sir James Ross and his 
companions carried on their deep soundings in the Southern seas, 
and found, as they very often did, at a depth of from 1,500 to 
