PROVISIONAL REPORTS, AND NOTICES. 439 
the great landslip took place in that neighbourhood, it might 
naturally be suspected that a part of the level line might be dis- 
turbed. A moment’s reflection made this appear improbable, 
since the movement seemed to be confined to the chalk and the 
clay below it ; whereas the terminus of the level line was bedded 
in the red marl. Still, if the movement of the ground were the 
result of an earthquake, even the inferior strata might have been 
slightly stirred; and this appeared to be exactly one of the 
cases, the decision of which was contemplated in the project of 
the level line. I therefore requested Mr. Bunt to repeat the 
levelling of the line from the mark in the church tower, in the 
village of Axmouth, down to the shore, where is the granite 
block which forms the terminus of the line, a distance of six 
sevenths of a mile. In July of the present year this operation 
was performed (with the same instruments as before), and it ap- 
peared that the mark in the church tower was above the mark 
RepeeaerlGcle | hata yeti al Ll wie elo Tor BBR S eats 
which in July 1838 had been found to be. . . 5°8805 feet. 
The difference, one twenty-seventh of an inch, may be consi- 
dered as a proof that there has been no sensible change. Mr. 
Bunt also leveled from the granite block, about 230 yards, to 
another bench mark eastwards, or towards the landslip, but 
found no difference of any importance. The expense of this 
operation, 10/., I have taken the liberty of including in the ac- 
count for tide discussions. 
W. WHEWELL. 
“Dear Sir, 
**I send you the results I have obtained from an elaborate 
investigation of ten years’ observations of the ‘ Displacement 
of Summit’ of the tide-gauge curves. The observed quan- 
tities themselves being so small, seldom exceeding 5 or 6 mi- 
nutes, I at first thought that they scarcely admitted of being 
treated in a similar manner to the ordinary observations of 
time and height, in which the corrections are gradually ob- 
tained, by approximation. On further consideration, however, 
I determined to try ; not knowing in what way to improve upon 
my former results. I therefore drew on the sheets a new line 
of observation (cutting off only the diurnalinequality), to avertical 
scale of 3 times the size of my old one, which had always been 
a scale of 40 min. per inch. ‘This afforded me sufficient size to 
go to work, on my former principles of approximation, by 
drawing in, on the line of observation, successive pencil curves 
of semimenstrual inequality, lunar parallax, and declination, 
and of solar correction, from the corrections first obtained, 
