THK VOVACK H.M.S. OFTALLKNUEIl. 
TIu' 80 , it will 1)0 soon, ;iro ;ill greater than the means of the live depths given above. 
'I’he lower spo<-ifio gravity of the Indian Oecan is due to the high latitudes in which 
they were olt.sorvod l>v the ('hallcnger. In the Atlantic, north of hit. 30° N,, twenty- 
fivo ob.servations give a moan of 1'02()5. Hence even at the bottom of the ocean the 
North .Atlantic continues to maintain a considerably higher specific gravity than any 
other ocean, and a higher tomj)crature is carried down to the bottom. Similar results 
arc shown bv rolativoK' high bottom specific gravities from Australia eastwards to long. 
15t)’ \V. botwoon (hdapagos and Panama, and to the east of Brazil, which are 
immediatolv connected with the higher specific gravities and accom])a.nying higher tem- 
pi‘nituros at ditforont ilepths of the.se respective regions. 
'Phe <-loso connection here indicated between the specific gravities and temperatures 
of the surface and the specific gravities and temperatures of the whole ocean down to the 
btittom, renders it diflicidt to overestimate the importance, in the further prosecution of 
thi.s intpiiry, of ;i corrc(-t knowledge of the mean annual specific gravity of the surface 
of the (M-ean. calculated from good monthly means which seldom appear in such publi- 
i-atioiis. It is from siuth means, along with the corre.sponding means of the annual 
icmp<^rature of the surface, that the discussion must proceed. 
V- 
