W. Hopkins on Changes of Climate. 73 
tose parts of the ocean through which they pass, and conse- 
Wently also that of the superincumbent atmosphere, and thus 
cailses the isothermals to deviate to the north of their normal po- 
sitions, . “Thus an examination of all the principal deviations of 
Hents are the principal general causes which produce irregularities 
in the forms of those lines; and, moreover, a know | 
catises enables us to: assign to. the isothermals their approximate 
land and ‘sea should be different from that which obtains 
‘he different hypothetical cases for which I shall endeavor to 
1) ne the isothermal lines are'the following :— ot 
rhe configuration of land and sea the same as at present, 
y 
