MARK. — SALINITY OF SKA-WATEU IN THE UEKMUDAS. 077 



to 1900 — for the position indicated. The teniperiiture and salinity 

 were determined as described in the precethng pages. 



Samples numbers 10, 20 and 22 were taken after lieavy rains and 

 therefore do not imheate the normal condition of the water. Samples 

 numbers 24 and 25 were collected by E. L. Mark and were brought to 

 Cambridge, where they were analyzed. 



The pipette and burette used in Cambridge were not the ones used 

 in Bermuda. The silver nitrate solution also was different and it was 

 standardized against a different sample of Danish water. The agree- 

 ment in the analytical results of samples 21 and 25, which were thus 

 determined absolutely imlependently, serves to increase confidence 

 in the reliability of all the analyses. 



Discussion of Results. 



The salinity of the water of the open ocean in the vicinity of Ber- 

 muda is undoubtedly that of the samples obtained off Nonsuch Island, 

 namely 36.43 grams of salt per 1000 grams of sea-water. These 

 samples were all collected outside the reefs, in positions exposed to 

 the unbroken swell of the ocean from the south. In taking an average 

 of the results, however, No. 19 has been omitted, as that sample was 

 collected under unfavorable conditions. The depth below the surface, 

 even down to 100 fathoms, appears to make no difference in salinity, 

 except after recent rainfall. 



The water of the shallow enclosed bays was found to increase in 

 salinity w ith remoteness from the open ocean. This becomes particu- 

 larly noticeable by comparing samples 2, 3, 4 and 9, where the suc- 

 cessive samples were collected farther and farther within the shelter 

 of the reefs and islands. The samples taken in Castle Harbor, also, 

 were in good agreement with predictions based upon the connection 

 of that bay with the ocean. The salinit\^ of the water from the 

 bottom of Harrington Sound, on the contrary, was surprisingly small, 

 as compared with that of other enclosed bodies of water. It was found 

 to be nearly the same as that of the open ocean, although the inlets to 

 this sound are so narrow that the tide rises only about one fourth as 

 much as it does outside. 



Summary. 



Data concerning the salinity and temperature of sea-water in the 

 Bermudas are presented. These indicate that the salinity is inde- 

 pendent of depth even down to 100 fathoms, but increases considerably 

 as the water becomes more and more enclosed. 



