the Ocean at Different Depths. — 11 
eter, and surrounded by a highly non-conducting substance.—The 
results are contained in the following table :— 
4ACES. E . 
Time of observa-| he Depth in at a 
: tion. enz. |Lat.w.| Lon. w.]| toises.* |° face : 
1/1823.) Oct. 10, Atlant. Oc. | 7° 21, 21° 59/ 539 25°, 80C. 2°,20 
2)1824., May 18, | So ith Sea. ee Paid 196 1 140,7 26,40 16. 
3 ee 6s “se 413,0 * “ss 3,18 
“ we ng6 ‘cs ‘ 6 665,1 2,92 
ra “ ss ‘c ‘sc 914,9 ‘“s x " 
61825. Feb. 8, « (95 6\155 58| 167 21,50 14,00 
« | Aug. 31, “ 32 6/136 48| 89,8 | 21,45 13,35 
‘ 6s “sé “ce “sé 214,0 ss i 1 
se ce ce sc “6 450,2 * 3,75 
ct See Se “ _ 6 «se “e 592,6 sé 2,21 
11/1826. Mar tlant. Oc. |32 20} 42 30 /} 1014,8 20,86. 2,24 
12/1825, ‘Aug. Hs South Sea. 41 12/141 58 205,0 19,20 5,16 
13] “« “sc “6 “ sc 512,1 “ce 2,14 
14]1826. Mar. 24,| Atlant. Oc. |45 58) 15 17 | 197,7 | 14,64 10 
15 | “* ss ‘e 96,4 ‘ec 9,95 
From this table the following conclusions may be drawn: 
1. Between the equator and 45° the temperature of the ocean 
decreases regularly to the depth of a thousand fathoms,—beyond 
no experiments have been made. __ 
2. The decrease of temperature is at ‘first a it gradually de- 
and becomes at last insensible. 
“8. The point where the decrease becomes ceaniatia appears to 
rise with the latitude. At 41° and 31° it is between two hundred 
and three hundred fathoms, at 21° it is near four hundred. ‘To this 
remark there appears to be a slight exception at 45° 53’, when the 
temperature at four hundred fathoms is still at 10° C. but perhaps 
at observation is modified by the proximity of the land, since it 
was made in the Atlantic Ocean only 15° W. from Greenwich, and 
consequently near the coast of Europe, while the others were made 
in the south sea far from any continent ; but even. in this case the 
point where the decrease of temperature becomes insensible is still 
evidently near two hundred fathoms. 
4. The lowest temperature observed is 2.29 C (36° F. ) and it 
is perhaps that of all the depths at which the decrease is insensible. 
The locality of that temperature rises with the latitude ; and it would 
be interesting to know at what latitude it reaches the pa i 
_The results of M. Lenz, in regard to the saltness of the sea, have 
been deduced from its specific gravity. It had previously been 
* A toise = 1.066 English fathoms. 
