CONTENTS. 



SUBMARINE OROGRAPHY. 



PAfIB 



1. The plummet — Brooke's deep-sea sounding apparatus . 1 



2. Construction of charts and sections of the ocean-bottom — 



But little as yet known of this subject — Maury, the 

 founder of submarine orographic science ... 8 

 'A. Analogy between the configuration of continents, and that 



of the bottom of the sea — Equatorial section of the earth 18 



4. Northern Atlantic Ocean— Chart of Maury . . .27 



5. The Mediterranean and the Black Seas — Chart of Biittgcr 31 



6. The Baltic— The North Sea— The Straits of Dover— The 



English Channel— The Bay of Biscay . . .37 



thh; vvatkr of the ocean. 



1. Composition of sea- water — Biot's apparatus . . .42 



2. Variations in the saltness of sea-water • . . . .47 



3. Variations oljserved in the gases contained in sea-water . 52 



4. Solid bodies in the sea — Phosphorescence . . .55 



5. Colour of sea-water — To what extent influenced by matters 



held in suspension, by the bottom of the sea, and by the 

 agitation of the water ...... G'i 



6. Measure of temperature at the bottom of the sea . . 68 



7. Diminished temperature of the sea in proportion to the 



depth — Irregularities introduced in this law by the in- 

 fluence of submarine currents — Temperature at the 

 bottom of the ocean constant and uniform — Principal 

 causes of submarine currents . . . . .70 



