ME. J. PRESTWICH ON SUBMARINE TEMPERATURES. 
597 
or one only 0 o, 5 less, at the bottom. As, however, there is little doubt that all these 
observations in Lyons Inlet were made with Marcet’s bottle, no reliance is to be placed 
on them*. In his third and last voyage of 1827 f, Parry made as many as. forty-five 
observations in the seas west and north of Spitzbergen, but none exceeded 700 feet in 
depth. With few exceptions, they show a lower reading than those of Scoresby. On 
this occasion he reverted to the use of Six’s thermometers. 
From Parry’s observing on his first voyage that his soundings were made with “ Six’s 
self-registering thermometer confined in iron cases” and again, on his second voyage, 
“ that he took out eight Six thermometers with iron cases” §, I was led, in conse- 
quence of the low readings, to think that these cases might have been used for protection 
against pressure; but Sir Edward Sabine, who was with Eoss in 1818 and with Parry 
in 1819, being in the latter expedition on board Captain Clavering’s ship, the 
‘Griper,’ informs me that all the observations were there made in concert between him 
and Captain Clavering, and that he had with him “ half a dozen thermometers on Six’s 
construction, made expressly for him by the elder Jones, each of which fitted into (and 
was retained by an apparatus at top and bottom) a tinned iron cylinder pierced with holes 
in the top and bottom, through which the sea-water percolated freely. .... The holes 
in the top and bottom of the cylinder were rather less in diameter than a seven-shilling 
piece, admitting a free current. A weight attached to the rope at some little distance 
below the thermometer, caused the line to run out freely, and prevented the occurrence 
of ‘ kinks ’ ” [] . 
It is therefore to be presumed that the iron cases referred to by Parry were merely 
to guard the instruments against accident, and not against pressure ; and on comparing 
the observations made by him on board the ‘ Hecla,’ often on the same day and nearly 
on the same spot, with those of Sir Edward Sabine in the ‘ Griper,’ I find them in such 
close agreement as to satisfy me that such was doubtlessly the case. At the same time 
* Of the 23 readings recorded, ten give precisely the same temperature at depths of 600 to 1200 feet as was 
found on the surface, while the others in no instance show a difference of more than 1°, and generally of not 
more than 0 o, 5 ; whereas an inland sea in those latitudes might he expected to show extremely low temperatures 
at depths. 
f Narrative of an attempt to reach the North Pole in the ‘Hecla’ in the year 1827. By Captain W. E. 
Parrs'. London, 1828, Appendix vii. 
X Op. cit. Introd. p. xiii. § Op. cit. Introd. p. xvi. 
|| Sir Edward Sabine thus describes the mode of proceeding in making the temperature-soundings: — “The 
cylinder, having the thermometer enclosed, was attached to the sounding-line, and was dropped into the sea 
from the extremity of a spar run out from the side of the ship, the line to which it was attached passing round 
a pulley near the end of the spar. In a similar way the cylinder when coming up from the bottom was waited 
for by a boat near the end of the spar, the cylinder released, and conveyed carefully by hand in an upright 
position to Capt. Clavering or myself at the gangway (or by ourselves), by whom the degree recorded by the 
index was immediately noted. The record by the thermometer was then written down on the spot antece- 
dently to any discussion or comment, the record being made either by Capt. Clavering or myself. The spar 
from the end of which the thermometer case was dropt into the sea was always several feet distant from the 
side of the ship.” 
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