[M.143L]                                                              [M.143]
                                                                      No 115.	San Giov & Paolo. Tombs. Traceries.	143
                                                                      
                                                                      No 115. is the leaf plinth of the nameless tomb. described at p 52
                                                                      		of M.2: in St John & Paul:  it is, (I think) in the southern
                                                                      		most chapel second from choir, on the north wall.
                                                                      		Its plinth is remarkable as a transition from the
                                                                      		Byzantine cutting to the luxuriant:  very sharp
                                                                      		and fine in effect: and second lobe not yet
                                                                      		projecting though this is no real criterion of age.
                                                                      		since the second lobes project in early capitals imitating
                                                                      		Corinthian.
                                                                      		The three lines of the section give the plinth, the fruit,
                                                                      		flower, or long leaf, and the short leaf: There is a central rib
                                                                      		to each main lobe: and a ridge between minor lobes.
                                                                      Traceries	Principal 4foil Tracery Let the two circles in the
                                                                      4foil		opposite figure be given:  To complete the arches between
                                                                      General		1st with a radius = span of arch
                                                                      Plan		Join centres C C2. let fall Cq C2b perpendiculars.
                                                                      		Make pq = CC2: with cent C  and dist Cq; desc.
                                                                      		circle qb: cutting C2 p in p b b Draw a b horizontal
                                                                      		then a b is abacus height, and the curves are
                                                                      		struck from centres, a and b.
                                                                      		2nd with radius = a b / 3  Find a c = 2 a b / 3: draw c d
                                                                      		vertical.  Make pc2 = a c from cent c describe c2
                                                                      		d cutting c d in d.  draw e f horizontal: then

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