Survey plan of the walls of Urbino
Measured stretches of the fortified perimeter with bearings
This sheet is headed 'The walls of Urbino.' It sets out a measured plan of the fortified perimeter, the length of each successive stretch entered around the circuit - a left-hand run from 38 down to 87, a short consecutive stretch (90, 65, 26), a squared corner element (b) with four equal sides of 70, and a full circular circuit of figures. Marginal notes give orientations, such as b, 36, a quarter from NW toward N, and a lower series of NW, W-toward-NW and NW-toward-N bearings tagged g.
On this page
Left-hand run of the perimeter
Read from the top, the left side of the wall circuit is measured 38, 42, 45, 70, 62, 20, 28, 8, 35, 14, 87. These are the successive stretches of the defensive perimeter.
Squared corner element b
A corner marked b is given four equal sides of 70, indicating a square tower or bastion at the angle of the walls. A neighbouring adjacent stretch reads b, 36, 34, b.
Circular circuit of measurements
A closed ring of figures - 26, 270, 160, 22, 15, 25, 30, 144, 12, 12, 13, 35, 145, 120, 43, 60, 76, 38, 80 - records the lengths around a rounded portion of the plan. It maps the perimeter segment by segment.
Compass bearings for the north-west sides
The continuation at the foot gives bearings tagged (g): NW 70 1/2, 70 NW, W toward NW 70 3/4, W toward NW 70 2/3, and NW toward N 34 1/2. These orient the north-west stretches of the wall to the wind rose.