mean annual specific gra 
Tlie "Voyage of H.M1S " Challenger 
LINES SHOWING THE 
MEANANNTIAL SPECIFIC GRAVITY (S* 
OF TIIE SURFACE OF THE OCEAN 
Traci of 104 
rk 
—pi - Tpp* IA-• 
\L 
V\ ■/ o 
ij % 
