f^x 



^'^ thof. 



e 



c 





^4ein(i 



n 



c 



'i, 



I 



"flite tras 



- Terv 



1 



f * 



-""-It it tit Fi 



^m^ to 



ncn 





,.,,., 



PC 



fjitfier in 



have 



• ^-Vc, at tk 



HUTTONIAN THEORY. 



435 



Thefe obfervations may ferve to fhow, how 

 unfound the principles are from which Mr Kir- 



wan s 



fions are deduced : they 



pe 



It 



haps more than is necefTary for that purpofe : 

 might have been fufficient to obferve, that the in- 

 creafe of land on the fea-fhore is limited, though 

 the augmentation from the land is certainly in- 

 definite, a proof that the diminution from the 

 fea is conflant and equal to the increafe. 



383. ** Mariners," fays MrKirwan, " were accu- 

 ftomed, for fome centuries back, to difcover their 

 fituation, by the kind of earth or fand brought 

 up by their founding plummets ; a method which 

 would prove fallacious, if.the furface of the bot- 

 tom did not continue invariably the fame*." 



I- 



The fad here Hated, that mariners, when na- 

 vigation was more imperfed: than it is now, 

 had very frequent recourfe to this method, and 

 that they ftill ufe it occalionally, is very true. 



r 



But from this, the only inference that can be 

 fairly deduced is, that the changes at the bot- 

 tom of the fea are very flow, and the variation 

 but little ; not merely from one year to another, 

 but even from one century to another. The 

 rules by which the mariner judged of his poli- 

 tion from the quality of the earth which the 

 lead brought up, and which were deduced no 



Ee2 



doubt 



* Geol. Effays, p. 440. 



