Mr. R. Fitch on the Coralline Crag. 463 



A = 9-5784-858. This constant at Liverpool appears to 

 have precisely the same value. I doubt whether much stress 

 ought to be laid upon any slight difference in the semimen- 

 strual inequality if deduced only from a few observations. As 

 this constant is the same for Liverpool and for London, I am 

 particularly anxious to ascertain from the Brest observations, 

 which I have not hitherto succeeded in obtaining, whether 

 it is the same for that port. 



I make for the Liverpool old docks, with parallax 57' and 

 when d = r, 



D = 8 ' E = 6-969 



and for the London docks, from the sill of the Dock-gates, 



Ft. 



D == 16-68 E = 4-44.8. 



Bernoulli's theory amounts to supposing the surface of the 

 ocean the same as if it were given by the equation 



Xdk+Yifly+ Zdz = o, 

 and therefore to neglecting the quantity 



u'dx + t/dy + w/dz, 

 which seems to require either that u\ r/, and ix/ are small and 

 negligible in comparison with X, Y, Z, or that the quantity 

 tt'd-r + i/ dy + w'dz is separately equal to zero. In order, 

 therefore, to prove a priori the justice of Bernoulli's hypo- 

 thesis it would be sufficient to estimate the value of these 

 quantities. 



Euler's method of considering the problem is the same in 

 substance as that of Bernoulli. 



LIX. On the Coralline Crag ofRamsholt and Orford. By 

 Robert Fitch, Esq. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 IT was with some surprise that I read Mr. Samuel Wood- 

 * ward's observations, in your last number, respecting a ter- 

 tiary deposit discovered between the Crag and the London 

 clay, on the banks of the Deben, near Woodbridge, and which 

 has lately been brought into notice by a paper by Mr. Ed- 

 ward Charlesworth inserted in the Lond. and Edinb. Phil. 

 Mag. and Journal for August. 



It appears that Mr. Woodward objects to the term " coral- 

 line crag " as applicable to the stratum at Ramsholt, and does 

 not agree with Mr. Charlesworth in considering that the beds 



