Ideal-city streets on many levels, and two incendiary bombs
High and low streets with cellars, courts, stairs and bridges; shells for the trebuchet
The upper half develops Leonardo's ideal city as a complex of high and low streets with cellars, courtyards, stairs, arches and bridges, keyed a b c d e f, with a second building complex sketched below. At the right he designs two incendiary bombs: one with its centre packed with powder to serve many small charges (scoppietti), the other a ball of pitch, sulphur and chopped hemp tow about 2 1/2 braccia across, filled with paper tubes of shot and cast from a trebuchet against ramparts. He notes the outer casing should burn so the enemy cannot steal the invention.
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Ideal city: complex of high and low streets (a b c d e f)
The upper half develops the ideal city as a complex of high and low streets with cellars, courtyards and bridges, keyed a b c d e f. Ramps, stairways and arches connect the levels in perspective.
Incendiary bomb with a powder-filled core
One bomb is to have its middle full of powder serving all the small charges (scoppietti), with a weight noted below it. The ring drawn at the right shows this cross-section.
Fragmentation bomb of pitch and sulphur for the trebuchet
The larger ball, some 2 1/2 braccia across, is made of pitch, sulphur and chopped hemp so its casing burns and hides the invention. It is packed with one-braccio paper tubes of one-pound shot around a bombard-ball or a holed, powder-filled bronze core, cast by a trebuchet against the bastions, with a single vent left for the fire.