9 



THE RELATION BETWEEN THE DEPTH OF WATER 

 AND ITS SALINITY. 



Over the reef in the iipi)er part of the pass and tliose at 

 the month of St. Johns Bayon, the water was always fresh, even 

 in the deepest places, irrespective of the direction of the cnr- 

 r( i;t. In the lower part of the pass there was, however, a notice- 

 able dift'crence in the salinity of water taken from the snrfacp 

 VI d that taken from a depth of from twelve to twenty ieot. 



The followino; table cyives a condensed acconnt of the dif- 

 ference in salinity of water from different depths taken over the 

 "Lip:ht House" reef. 



TABLE 1. 



Sali.'iity. 



Date. Direction of Current. Surface. 16 Feet. 



May 8th. Down 1.000 1.000 



May 9th '' 1.000 1.002 



Mav 10th " 1-000 1.004 



Mav nth " 1.000 1.0042 



^lav 12th " 1.000 1.0035 



:^la'v 13th Up 1.000 1.0051 



:\raV 14th Down 1.000 1.0029 



Yrv 15th " 1.000 1.0033 



^lay 16th ' 1.000 1.0046 



May 17th " 1-000 1.0039 



May 18th '' 1.000 1.0047 



May 19th Up 1.000 1.0051 



May 20th " 1.000 1.0073 



June 1st Down 1.000 1.0035 



June 2d '' 1.000 1.0074 



June 4th Up 1.0052 1.0095 



June 6th " 1.010 1.012 



June 8th Down 1.0085 1.011 



As shown in the table, the water was always more saline 

 a<- the {greater depth and, at a depth of 16 feet, the salinity was 

 sufficient to alloAV the oysters to maintain life. 



The reef over which the water was taken to make the sa- 

 linity records given in the previous table, begins above low water 

 nark and extends out toward the channel to a depth of about 





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