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left that part fpherical, being one of thofe ftones, 
in which one part of the fame end is flat, and the 
other convex, fwelling like a cuihion. 
This ftone I fent as a Angle ftone. It is a large 
octagon, twenty three inches over ; but after it had 
been fome time in my garden, I perceived a crack 
in it, and, applying force, it divided. The under 
ftone had been fo unequally prefs’d, that it is not only 
very thin on one fide, but there is a large hole in it, 
about feven inches diameter, very near the edge of 
the ftone j fo that the matter muft have been prefs’d 
away to the other flde of the ftone, not equally con- 
cave, and the ftone above it muft have prefs’d into 
the ftone below this j in which lower ftone the con- 
vex part, which prefs’d through the middle ftone, 
muft have been left, as it is broken : which I did 
not obferve at the Caufeway. 
Some ftones at the fame end are partly concave, 
and partly convex ; probably occaflon’d by fuch an 
unequal preflure ; fo that I have one, which meafures 
nine inches deep on one fide, which is convex, and 
four and a half on the other, which is concave: an- 
other, tho’ all convex, yet is fix inches clear at one 
angle, and only four at the oppoflte angle j fo that 
in thefe ftones the joint appears as indented. 
We are to fuppofe, that, generally, the top of the 
lower ftones is convex, and the bottom, confe- 
quently, of the ftone, that lies upon it, concave. 
But as fometimes both ends of a ftone are concave, 
we muft fuppofe, either that the lower part of the 
ftone, which fettled on it, was harder, or, being of 
equal hardnefs, by its gravitation prefs’d it down. 
G g Since 
