by ribs and buttresses ingeniously disposed, so as to bring the weight of the lantern to bear on the base of the dome.
A sketch underneath it shows a round pillar on which is indicated which part of its summit is to bear the weight: "il pilastro sara charicho in . a . b." (The column will bear the weight at a b.) Another note is above on the right side:Larcho regiera tanto sotto asse chome di sopra se(The arch supports as much below it [i. e. a hanging weight] as above it).
Pl. C, No. 1 (C. A. 303a). Larger sketch of half section of the
Dome, with a very complicated system of arches, and a double vault.
Each stone is shaped so as to be knit or dovetailed to its
neighbours. Thus the inside of the Dome cannot be seen from below.
MS. C. A. 303b. A repetition of the preceding sketch with very slight modifications._]
[Figs. 1. and Fig. 2. two sketeches of the dome]
MS. Tr. 9 (see Fig. 1 and 2). Section of the Dome with reverted buttresses between the windows, above which iron anchors or chains seem to be intended. Below is the sketch of the outside._
_PI. XCIX, No. 3 (C. A., 262a) four sketches of the exterior of the Dome.
C. A. 12. Section, showing the points of rupture of a gothic vault, in evident connection with the sketches described above.
It deserves to be noticed how easily and apparently without effort, Leonardo manages to combine gothic details and structure with the more modern shape of the Dome.
The following notes are on the same leaf,_ oni cosa poderosa,