——o 
Slashdot heer 
oat 
aw 
hyse J 
to the rule of that writer; a continuation of AB determines the 
angles of the outward and circular buildings NO: a tangent to 
the circle drawn parallel to this line fixes the hypofcenium R 5, 
and the principal entrances anfwer to the vertices F, I of the two 
triangles whofe bafes cut the {cena at right angles. 
Dean Marti fays the diameter of the orcheflra is ninety-fix 
palms, or fixty-fix feet Englifh; but in this he muft include the 
firft bench, the orcheftra being only fifty-eight, and the bench four 
feet broad: he is miftaken greatly in the meafurement acrofs the 
whole from angle to angle N O, by him ftated to be three hun- 
dred and thirty palms, or two hundred and twenty-fix feet and 
eleven-twelfths Englifh; which fhould have been given as the 
extent of the fquare part of the building PQ, The diame- 
ter NO from angle to angle is two hundred and eighty- 
three feet, and confequently from the conftruction of the theatre 
the exterior femicircle from N toO, including the platform that 
communicated to the corridor leading to the benches of the people, 
was four hundred and fifty-three feet fix inches*, that is, a diameter 
and a half and twice the fourth part of a diameter of the or- 
cheftra. Where the dean found a femicircle of five hundred and 
fixty-four palms, or three hundred and eighty-feven feet and an 
half Englifh, I cannot conjecture. The height + that he afligns to 
the fumma cavea is one hundred and thirty-three palms and an 
half, 
* Lipfus: Cap. 8 de Amphitheatro. Theatrum non jufti hemicycli forma fed 
amplius diametri quarta parte fuit. ; 
+ See the fection, plate 3. 
