MAPS AND PLATES. 



To face 

 PLATE page 



I. TRACK OF H.M.S. 'LIGHTNING' 1868 59 



II. FIRST CRUISE OF H.M.S. ' PORCUPINE '1869 87 



III. SECOND CRUISE OF H.M.S. 'PORCUPINE' 1869 95 



IV. THIRD CRUISE OF H.M.S. ' PORCUPINE '1869 106 



V. TRACK OF H.M.S. ' PORCUPINE '1870 180 



VI. DIAGRAM OF THE 'PORCUPINE' SOUNDINGS IN THE ATLAN 

 TIC AND IN THE FIERCE CHANNEL, SHOWING THE EELATION 



BETWEEN TEMPERATURE AND DEPTH, THE SERIAL SOUND 

 INGS REDUCED TO CURVES. TlIE NUMBERS REFER TO THE 



STATIONS ON THE CHARTS, PLATES II., III., AND IV. ... 323 

 VII. PHYSICAL CHART OF THE NORTH ATLANTIC : SHOWING THE 

 DEPTH, AND THE GENERAL DISTRIBUTION OF TEMPERATURES 



FOR THE MONTH OF JULY 363 



VIII. MAP SHOWING THE GENERAL DISTRIBUTION OF THE TER 

 TIARY, THE CRETACEOUS, AND THE JURASSIC SYSTEMS 

 IN THE NORTH-WEST OF EUROPE WITH REFERENCE TO 

 CONTOUR 474 



