D/vblagden on the Heat, &c. 
with certainty when (he enters into the Gulf-ftream is attended 
with the further ineftimable advantage of (hewing her place 
upon the ocean in the moil: critical fituation : for, as the cur- 
rent fets along the coaft of America at no great diftance from 
foundings, the mariner, when he finds this fudden increafe of 
heat in the fea, will be warned of his approach to the coaft, 
and will thus have timely notice to take the neceflary precau- 
tions for the fecurity of his veffel. As the courfe of the Gulf- 
ftream comes more to be accurately known, from repeated ob- 
fervations of the heat and latitudes, this method of deter- 
mining the fhip’s -place will be proportionably more applicable 
to ufe. And it derives additional importance from the peculiar 
circumftances of the American coaft, which, from the mouth 
of the Delaware to the lbuthernmoft point of Florida, is every 
where low, and befet with frequent fhoals, running out fo far 
into the fea that a veffel may be aground in many places where 
the fhore is not to be diftinguiflied even from the maft-head. 
The gulf-ftream, therefore, which has hitherto ferved only to 
increafe the perplexities of feamen, will now, if thefe obfer- 
vations are found to be juft in practice, become one of the chief 
means of their prefervation upon that dangerous coaft. 
